Hot!EVGA EPOWER V - User's guide and installation tips.

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2019/02/11 01:20:41 (permalink)

Refreshed EVGA EPOWER V "The Untouchables" stand-alone power board returns. It's been some time since release of the previous Gen 4 model in 2013. EVGA EPOWER module is handy and versatile tool to provide more juice to various graphics adapters, especially physically and power constrained reference designs from NVIDIA and AMD. This is crucial for extreme overclocking with liquid nitrogen cooling.

This is fifth version of the EPOWER project, released in retail for extreme overclockers and hardcore enthusiasts. It gets the label "Generation V" for this reason. Previous EPOWER Gen 4 Classified with blood red PCB resembled EVGA GeForce GTX 680 Classified power solution. New EPOWER V leverage more efficient and higher power VRM from EVGA GeForce GTX 980Ti K|NGP|N Edition card. VRM was further tuned up with latest IR3575/IR3579 Infineon PowerStages that have improved thermal performance.

EPOWER V has synchronous buck DC-DC converter with no less than 12+2 phase layout. Such converter use input +12VDC voltage from standard PC PSU to provide stable and regulated 0.6 - 2.0V output voltage, at maximum loading over 600 Amp. Additional 2 phase DC-DC regulator used for second voltage rail channel, with individual control and current capability up to 90 A. Second channel can be used for memory power on graphics card or PEX/PLL power.

Since different VGA cards may require different output voltages, both settings are adjustable in real-time. In this article we will cover common use scenarios and possible ways to adjust voltage, protection limits and other available tweaking knobs.

As with previous EPOWER's, connection to target graphic card is done by direct soldering with heavy gauge copper wire, or better, solid copper plates. Due to high currents and low voltages, it is essential to have minimal resistance at interconnect between the VGA card and EPOWER. Wide and short connection is the main rule here.
Due to complexity of use, EPOWER V is covered only by special DOA(Dead-on-arrival) type warranty. Meaning that every single EPOWER is tested before shipment and can be replaced only if it's not working out of the box, with only ATX PSU attached to it. If you modified your VGA, soldered EPOWER down, there will be no replacements possible. Be sure to check EPOWER correct output prior to connecting it with VGA card.


Before we dig deep into details, here's required part:

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All information posted here is hosted just for education purposes and provided *AS IS*. In no event shall the author, this site, or any other party, including EVGA be liable for any special, direct, indirect, or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortuous action, arising out of or in connection with the use or performance of information published here.

This product is intended for use by advanced users with good understanding of computer parts function, decent soldering skills and experience in extreme overclocking. There is no benefit to use such device for everyday gaming, as native VRM on the graphic card is a good match for everyday use cases.

If you do not agree with risks involved, do not perform the any modifications.

EVGA EPOWER V theory and design

Before we start any soldering and testing let’s take brief tour into typical VRM (Voltage-Regulation Module) design. VRM is a device, usually in form of circuitry on PCB which consist of DC-DC converter and controller, which provides a load the appropriate power supply voltage. This is achieved by using switching regulator that convert high input voltage (such as +12.0 VDC from PCIe power cable) to a much smaller voltage level required by the load specifications. Since the total power is the same, lower voltage allow to source much higher currents, used by all those billions of transistors inside the CPU/GPU.

Load here and further in article meaning target device, such as central processor on motherboard or GPU(Graphics Processing Unit)) on graphics card. From power supply point of view, it doesn't matter what is used as load, it could be even piece of heating wire. Common and important thing is that load sink provided current, depending on its dynamic and static internal resistance. Task of VRM is to provide that current and regulate output voltage stable, with any changing load conditions.

Why not to supply already regulated lower voltage from the PSU directly? Answer to that question is resistance of interconnects and power loss on wires. Modern GPU can easily sink over 200 A of current, which means use of very heavy gauge wires. Since GPU also have strict voltage regulation demands (usually 5% or better) there is no way to provide that much of current with any reasonably sized (and priced) wires or connectors to lengths over few centimeters (inches). That's why any typical motherboard or graphics card has these switching DC-DC converters onboard, right next to CPU/GPU. Sometimes VRM are installed as daughter boards in a dedicated high-power connector (common to see such VRM modules in rack servers, where every inch of space is vital).

It is easy to recognize power regulator circuit by proximity with high-current ferrite inductors and banks of capacitors. Multi-phase regulators have all phases grouped together, to maintain current and thermal balance across phases. Proper spacing to rest of the sensitive circuitry on the PCBA (memory, I/O interfaces or onboard controllers) is implemented due to large amounts electrical noise generated by switching components in VRM.

Some voltage regulators provide only one fixed level supply voltage to load, but most of them can provide mechanism to adjust the supply voltage from the load using some form of interface, be it parallel VID signals, or even simple analog feedback circuitry. Multi-phase VRMs that designed for modern CPU or GPU power also can use dedicated digital bus, such as I2C/SMBus/PMBus or SVID/PWMVID to get necessary data for operation and reporting.

Image above show typical high-level VRM map of VGA card. Ignoring number of phases and type of connectors, every VGA card is build this way. Two important logic signals, VRM_ENABLE and PWR_GOOD are discussed in next chapter.

VRM controller also needs its own power supply voltage to operate. This is usually system auxiliary low-voltage rail, such as +3.3 VDC from the PCI-express edge connector. +3.3V voltage is used for digital domain of VRM, like PWM controller, onboard clock generation, control circuits and various onboard logic. +3.3VDC often used by other controllers and I/O devices, SLI interface power, BIOS, hardware health monitors, I/O detection logic and such. That's why PCI-Express CEM standard for AIC(Add-In Card) always have +3VDC and +12VDC power inputs at PCI-Express slot edge connector. +12V used for lower power DC-DC and +12V from separate 6/8-pin power cable from PSU.

In this article we will study few examples of VRM circuits and will learn few things how to use, control and override these converters. EPOWER V is a great example to learn all related knowledge. This is especially important for overclocking and performance testing, as voltage margining can act as the key for higher frequencies.

Many controllers allow shutdown control and power good status reporting. For that dedicated GPIO signal line and pins are used. Such signals described as "ON/OFF" or "VR_Enable" or simply "Enable" signal and power good status reported via "VR_RDY" or "PWR_OK" signal/pin.

Enable signal in VRM operation

Purpose of VRM_ENABLE signal is to provide ability to turn on (Enable) or off main VRM by our GPU or other smart monitoring circuitry that may be present onboard. This signal has *input* direction, feeding signal into VRM controller. Let's take simple example in term of generic 1080 Ti videocard depicted on _Image 4_ above. 1080 Ti GPU used on this card have special GPIO pin hooked to VRM_ENABLE signal on PWM. During startup I/O block of 1080 Ti chip pulls this signal high, thus giving command for VRM to start operation and power-up. VRM begin to operate at nominal level, which is around 1 VDC output. Once output reached stable regulated level, VRM controller activates PWR_GOOD signal, which is often tied to GPU's RESET input, and let GPU start initialization and boot. If for whatever reason PWR_GOOD is not active (stay low level, 0V) then GPU will be kept in RESET condition and will not boot.

Why we need such arrangement, and not let VRM to start and run on its own. This "ENABLE" handshaking between GPU and power regulator allow to implement protection mechanism, for example overheating protection. Assume that user forgot to connect fans on cooler, resulting critical GPU overheat while VRM operation continue to power the chip. VRM still feeding GPU with nominal voltage, as it can't know anything about GPU temperature. GPU will cook itself to death short if no action taken quick.

However, during overheat event GPU chip can sense its temperature and forcefully pull down VR_ENABLE pin to 0 V. As result of this VRM now will immediately shut down output voltage, as result preventing possible damage to graphics card GPU. Do not confuse this with other software-controlled shutdowns or protection triggers, such as OCP or OVP trip, which are internal to VRM. Protection trips are detected by VRM controller internally, and are not related to external logic. Such events can be reported by PWR_GOOD signal.

VR_ENABLE can be also controlled by simple detector logic circuitry based on small NPNs or NFETs to always enable VRM if input power voltage +12V or +3.3V rail voltage from PCI-Express slot is present. This is why if you don’t have +3.3V/+12V power on PCIe slot VRM will be permanently disabled no matter which voltage we give to PCIe 6-pin power connectors.

Power good signal from VRM

Now few words about *VR_RDY* (Voltage regulator Ready) or *PWR_GOOD* (Power Good) signal. In a way it has reversed meaning of VRM_ENABLE. This signal is *output* direction, from VRM controller. When this signal is active high, VRM is reporting normal operation, with stable and controlled output voltage, at rated settings, currents and temperatures. This is often used in high-end cards to monitor state of VRM to detect faults and assert shutdown before critical failures progress further. For example, if MOSFET in phase blows up, VRM see that phase current levels reach critical limits and reports failure to system dropping PWR_GOOD. Similar method is used in usual ATX PSUs btw, by signal Power Good.

Now let's take a look on same block diagram, but with GPU power coming from EPOWER.

Standalone power supply module, such as EVGA EPOWER V is designed to replace onboard VCORE regulator too allow higher capacity power delivery. This is beneficial for extreme overclocking use, as onboard DC-DC power converters on reference design are often not adequate for high voltage/high loading Extreme OC scenario. Often onboard regulators also lack of adjustment range, so you may be limited to lower voltage, than actual GPU can run before having thermal/stability issues.

While isolated supply module gives us flexibility, it also does not come free. Difficulty of running card with EPOWER is due to inherent lack of sync between onboard VRM controller and EPOWER's controller, as these are two separate controllers. So typical solution is to completely disable onboard VRM, isolate it from GPU and use EPOWER instead.

Same as Gen 4, board accepts input voltage from triple MiniFit Jr. 6-pin connectors, following typical PCIe VGA pin out. Input voltage range is +10.6 to +13.2 VDC, easy requirement for any high-end 1000+ Watt ATX PSU. For heavy loading, such as Titan Xp + EPOWER at least 1200 W single-rail PSU is recommended.

EPOWER V has two four-digit LED displays, which indicate current voltage on both channels. On key press setting value for output voltage is displayed. More on controls later in this guide.

Latest generation is also more flexible now, in terms of use and hardware support. Firmware can be reprogrammed by user to allow special cases, when additional features or functions, such as protection, loadline tuning or monitoring are required. This may be crucial for overclocking modern cards, such as AMD Fury/Vega or NVIDIA Titan X/Xp. Additional firmwares will be made available thru this guide or in this thread.

EPOWER V using Infineon VRM controller, IR3595A. Key feature list:

* 8-phase single or 6+2 dual loop configurable PWM Controller. Here it's used as 6+1 dual loop.
* 8-bit PVID, PWM VID or I2C set point control on loop 1
* Serial I2C set point control on optional loop 2
* Programmable Constant Current Protection
* Min/Max Telemetry registers and real-time monitoring via I2C (IIN, VIN, IOUT, VOUT, Temp)
* IR Adaptive Transient Algorithm (ATA) minimizes output bulk capacitors and system cost
* IR Efficiency Shaping Features including Variable Gate Drive and Dynamic Phase Control
* Protection: OVP, UVP, OC Warn, OCP, OT Warn, OTP

Loop in power terminology here is referred to output voltage channel. Due to safety reasons, maximum output voltage is limited around 2.000V. Most modern VGA cards have capacitors on Vcore rated only up to 2.000V, and will max out overclocking at much less voltage, even under liquid nitrogen -196 °C cooling. Solid capacitors may have nasty explosions and fire if overvoltage happens, so voltage limits greatly reduce this risk.

EPOWER board can be a very handy tool for new GPU testing, as it can be used the moment we get the reference cards for overclocking. Based on those test results, not limited by power constrains of voltage limits, finalized custom designs like KINGPIN Edition and FTW3 emerge, which essentially have both EPOWER and GPU circuitry already integrated on the same PCB, without any mess and wires.

Also onboard controls are added, so no external EVBOT dongle required to get voltage readout of real-time voltages on both VCORE and VMEM rails. Output voltages can be also freely adjusted at any time by onboard keypad.

Feature overview

Here's quick fact sheet with main features list on this latest generation EVGA EPOWER V VRM.

Dual-channel powerful output

EPOWER Gen 5 can source over 620A of current with typical output voltage 1.6-1.8V. Maximum voltage available is 2.0V on main VCORE output. Additional memory VMEM channel supports voltages up to 2.3V and source current up to 90A. Remove sense option is available for both rails to obtain accurate voltage regulation.

Onboard voltage LED display and integrated EVBOT function

Previous generation EPOWER required external controller for real-time voltage adjustment, one of which is EVBOT. Today just few overclockers have EVBOTs, so to address this new EPOWER have onboard fully integrated controller, which allow adjustments of both voltage output channels in real-time. Voltage readouts are calibrated to DC accuracy better than 3%.

Embedded self-diagnostics

On each power up onboard controller checks all voltages, test interface operation for VRM controller and verify input signals. This takes just a moment and result of diagnostics briefly displayed on the screen. In normal conditions you should just see brief "TEST PASS" message.

Future-proof USB-C interface

Onboard USB Type-C connector provide interface between EPOWER and host PC. This allow to field firmware upgrades, to support upgrades and compatibility with new graphic adapters. Update procedure is simple and involve just USB A-C cable to computer.

ProbeIt monitoring header

Standard connector to attach external multimeter or oscilloscope for spot checks and operation monitoring. Output VCORE, Output VMEM, Onboard +3.3V, +5 and input +12V voltages are routed to ProbeIt, interleaved with ground return terminals.

Output voltage status also displayed by on-board white LED, just like EVGA GeForce GTX K|NGP|N Edition series cards.

Fan headers

Typical use case requires minimal airflow at EPOWER's power circuits. Onboard +12V 3-pin support two fans. There is no PWM control, and fans will run 100% speed once connected to EPOWER. Unlike typical motherboard fan headers, each of EPOWER headers support high-speed high-power fans for system cooling, up to 3 A each.

Droop, Force and Offset voltage HW switches

Few advanced hardware controls available for power users. Offset switch *VOFS* bumps VCORE output voltage 80mV/switch, adding max voltage of 0.16V to the present value. This is independent control, handy is you needed higher boot voltage on system power on.

*Force* switch disable protection mechanisms to force power output, even when EPOWER overloaded.

*Droop* controls compensation and remote sensing operation. This is important function to compensate for voltage droop on high-power VGA's, such as 980Ti or Titan X (Pascal).

Triple 6-pin power inputs

EPOWER V does not allow hot-plugging, hence there is no detection pin required. As result all three pairs +12V ATX PCIe Power connector, which is 6-pin MiniFit.Jr type are available as power input. Such connector configuration support 33A 12V, using typical 16AWG cables from high-end computer power supply. This is based on rather conservative +30°C temperature rise over ambient for the connector pin. In typical system, with forced airflow from cooling fans, three 6-pin connectors allow 100A+ input currents. Simple napkin power math calculation helps to understand available power budget easy:

PMAX = IMAX * V12V; PMAX = 100A * 12.0 VDC = 1200 W MAX

Where *PMAX* is maximum input power, *IMAX* current rating and *V12V* is input voltage from the system power supply. With help of IR3575 PowIRstage(R) Datasheet VRM efficiency can be estimated at level ~90%, with 94% peak at 216A load. However typical use of EPOWER will be at full loading, so calculation below is for worst case.

POUT = PMAX * 89% efficiency;* POUT = 1068 W; IOUT = POUT / VOUT; IOUT = 1068 W / 1.65 VDC = 647 ADC

Where *POUT* is available output power with VRM efficiency in math, *IOUT* available current rating and *VOUT* typical output voltage, chosen in math above to be equal 1.65VDC. Now we can also estimate power loss on conversion.

At output current 647 A regulator will have 55 A per phase, which cause *9 W* of power loss per phase. With total phase number equal 12 for main VOUT rail that is *9 W &times 12 V = 108 W*. Such power level mandate active airflow. If heatsink and PCB kept cool, IR3575 power stage silicon die temperature can be calculated using datasheet's *θJC_TOP* thermal resistance specification.

*Die ΔTrise = PLOSS * θJC_TOP;* Die ΔTrise = 9 W * 1.7 °C/W = *+15.3 °C*.

With ambient temperature +30 °C die temperature will reach only +46°C, if heatsink kept at same temperature. In more realistic case, heatsink will have 30-40 °C temperature rise, which is within safe margins for IR3575 specification of TJMAX = +150 °C.

This calculation is essentially same for every DC/DC design converter, and it's good idea to practice it for better understanding of power derating and importance of high efficiency. Such math applies to motherboard, graphic card VRMs and even ATX power supplies, if all used component specifications are known. Suggest to run own numbers with different output voltages/currents to match your case.

All three power input connectors must be plugged, as phase power balancing is done in hardware to sink current equally from each connector. Good airflow over the board is highly recommended for optimal performance with higher power levels.

EPOWER V Usage methodology

Detailed step-by-step guide in this section show typical use scenario for EPOWER V. Following the guide can help you achieve best results with this extreme overclocking product. Older guides can be used as reference as well, the overall concept and application remain the same.

To use external power regulator board, such as EPOWER V successfully follow next set of rules:

* Think carefully about the end ultimate goal, carefully and in detail. Modern graphics card VRM solutions become much better over last few years, and totally sufficient for normal use, gaming, even overclocking on water-cooling. However, to overclock card to the ultimate limit under subzero cooling with CO2 dry ice or LN2 liquid nitrogen, you may quickly run into power issues, and that's where you consider using EVGA EPOWER V. So plan properly. It's very unlikely that anyone would buy VGA card which was subjected to heavy PCB modifications, required to use EPOWER.

* Every power wire should have short return path wire for current. Good idea to have two return wires for every power wire. Electricity flow in closed loop circuit, using *TWO* wires, forward (positive VRM output) and return (GND or ground zero). This is why you always have two contacts in your home mains power outlet, not one, but two (for simplicity, earth terminal is omitted, it carries electric current only in critical failure condition).

* Keep things simple. Do not do stuff you don't understand completely. Practice on something easy and cheap before starting complex things, and practice first on low-end old graphic cards, which you don't care much about. Once you have solid skills to apply all required mods, proceed with higher end equipment with better skillset.

* Keep high-power paths and connections length SHORT and WIDE. More length – more voltage drop, more EMI pickup, more noise from power regulator. So lots of headache with long wires is a guarantee. This is why all power connection on VGA, Motherboards, CPU boards whatever are made with solid copper planes, to have shortest path possible for all those large currents. I would not use anything less than AWG14 for such high-power low-voltage VRMs. This rule also suggests to connect wires as close to load as possible. Usually nearest comfortable spot to connect is original VRM choke contact, from load side. You will anyway have to desolder chokes, so you already have nice solder point to start with there anyway.

5. Remember, electronics is a science about contacts. No contact where it should be – failure. Contact where it should not be – failure. Recheck and check every step of the process as you progress to get successful results. Never power up anything until it is fully checked every component and every connection. Remembering that you have only one GPU to blow up in case something goes haywire may help. These checks might feel like waste of time, delaying overclocking session by hours, sometimes even days, but it’s actually saving time, money and hardware (not by burning it, or making awful results) in long term.

Uncorking BIG KELPER - practical guide for beginners

Using EPOWER Gen.2 on GeForce 8600 GTS card

KPC: Zombie EPOWER Titan Guide

STEP 1 - Prepare workbench area and gather all required tools

* Target device, in our case EVGA GeForce GTX 1080 Ti reference graphics card
* EVGA EPOWER V power module
* AWG12 or AWG10 copper wire with insulation or copper plates
* High power soldering iron, 120W+ recommended for copper plates
* Generic digital multimeter for resistance and voltage checks
* 80/120mm +12V DC FAN with 3-pin header for VRM cooling
* Some flux and solder for wire joints
* Insulation materials to prevent moisture on VRM
* Sharp blade to prepare insulation
* LN2 extreme cooling container for GPU cooling, such as Kingpincooling.com TEK-9 FAT

Many enthusiasts and overclockers already have most of the items from this list, only new thing - copper plates. I found them to work best than heavy gauge wires, because they are not flexible and less troublesome to keep in fixed position. However, they have large thermal mass, and need high power soldering iron, at least 120W. I use high-power ERSA iCON 1 soldering station. Also copper plates after shaping can be reused for multiple cards. Also no burning wire insulation and nasty smoke from plates, which is better for overclockers health.

Suggest to perform all modifications with good bright lights, so you can see clearly what is going on. Some additional gear, like pliers, magnifying glass, set of wires could be useful on various steps. Taking few photos during the process may help later to showcase the result in your benchmark submissions .

One can buy these copper sheets at local PC cooling parts shop, but pretty sure those are not hard to get all over the world in some metalwork shops, etc. Thick copper foil (0.5-1.5mm thickness) would work too, just combine few sheets together to provide nice robust plane.

When carving copper plane shapes, ensure the plane shapes are reasonably square in shape. Avoid having a long and narrow plane shape because this limits the current flow and increases plane parasitic inductance and loss.

STEP 2 - Remove onboard VRM inductors

Remove heatsink from the VGA card. It's easy to locate power regulation circuitry on the videocard.

You can overlay EPOWER to estimate best placement on the card. It is important to keep shortest distance possible between EPOWER output exposed metal area and VGA card VRM power inductors. Short and wide connection allow better voltage regulation and stability.

Main GPU VRM circuitry usually located on the right side PCB, between GPU and power input connectors. It's easy to spot one by location of big high-power inductors, which look like gray rectangles with two massive contacts. Now since our goal is to replace onboard power regulation circuit with EVGA EPOWER V module, we need to isolate onboard regulator, and expose copper to have clean power entry path.

At this point you can also check how much space is required for your GPU cooling solution. It would be a sad moment, if all the work done only to find out 2 mm interference with the LN2 container preventing setup from assembly.

Removing inductors (marked R22 Power choke) will do exactly that, disconnect GPU power input from the onboard VRM and leave large area with metal plane to allow EPOWER connection. That's where output of the EPOWER VRM will be connected once we find best spot for whole assembly.

Desolder original inductors of each GPU voltage phase with high-power soldering iron. On GeForce GTX 1080 Ti there are 7 inductors, marked LR22. Leave smaller R22 inductor near top edge of the board intact, that one is used for separate memory VRM circuitry.

One side of inductor pad go to VRM MOSFET stage by rather big polygon (solid copper plane) and opposite side connected across all output inductors, array of power filter output capacitors and enter internal layers to provide solid connection to GPU power pins. Idea of using EPOWER is follow same concept, so we need to connect power output from EPOWER V PCB to this output capacitor polygon as good as possible, thus having power flow into original power planes from external source.

Usually good idea to keep memory power delivered from onboard regulator. Typically, you would need memory attached to EPOWER only on older cards, or dual GPU cards to avoid power balance issues. If you decide to have memory powered from EPOWER V as well, remove memory power inductors too.

Now need to take care of *PWR_GOOD* signaling.

STEP 3 - Make sure PWR_GOOD is activated to allow GPU operation

Since such condition without inductors in terms of onboard VRM controller considered open phase and undervoltage fault, it will shut down output and will keep power stage FETs disabled. Exactly what we need, no need to remove other power components to disabled VRM. The only trick is that VRM controller also deactivate PWR_GOOD signal, which as we learned before will disable the GPU. Cut the trace right at the VRM controller to prevent PWR_GOOD signal from it going onto the card. This sometimes can be tricky because of small trace width.

Also make sure that PWR_GOOD on the remaining trace is still activated (held high, +3.3V or +1.8V level when card is powered, with inductors removed). This step required to confirm our GPU is enabled and all it needs is actual power output from the EPOWER to be working again. If PWR_GOOD is still equal to zero, you may need to solder small 1.0...4.7 KOhm resistor to nearest +3.3V point. You can trace +3.3V by probing PCIe +3.3V pin and components near VGA's VRM controller with DMM, set to lowest resistance measurement range, such as 200 Ohm.

For more details on which trace is PWR_GOOD (sometimes called *VR_RDY* or *READY*, depends on controller) on specific card try to find datasheet for the specific controller used on your card, or consult with all-knowing Internet.

Memory VRM may also have same PWR_GOOD signal, that can enable/turn on secondary VRMs, such as PEXVDD. Make sure that one is correct as well. If it's not high +3.3V/1.8V when card is powered on, add a pull-up resistor as described above. You must have all rails operational at power on, otherwise GPU will not start.

STEP 4 - Expose copper plane for ground and power on target device

Now we removed onboard inductors, ensured correct level of PWR_GOOD signal and ready to proceed for additional copper cleaning to get larger soldering area to EPOWER. More surface area between VGA and EPOWER improve connection quality and reduce unwanted parasitic resistance. Do not skip on this step, as even small resistance increase of 10 mOhm can cause significant voltage losses and issues at high current levels. Modern GPUs can easily sink currents over *200-400 A* under extreme overclocking conditions, or even more in short peaks under heavy load!

Solder mask is hard coating on the PCB surface that protects outer copper layer and provide electrical insulation to avoid shorts. On VGA this mask often colored black, but it can be different colors. Mask coating is chemically and mechanically robust, so typical solvent such as acetone or IPA will not be able to remove it.

Easy way to remove mask is use mechanical tools to remove thin layer, exposing bare copper metal for soldering. Inspect the area carefully, to ensure there are no isolated via (PCB pad with metallized thru-hole drill) for other signals. We need expose copper connected to GPU power. Best area to start with is outputs of the inductors (left pad on photo above).

You can use any tool suitable for scratching etc. While it's OK to do so with sharpie, it's possible with careful use of small grinder, such as Proxxon FBS 115/E with sandpaper cylinder tool on it.

Take care not to expose or short any other traces on PCB, or you will need to repair broken connections. Use minimal speed and avoid applying force, to reduce risk of knocking off nearby PCB components damage or going too deep into PCB layers. After some "shhrrr-shhrrr" action, you should have nice and shiny clean copper surface on power plane, ready for soldering.

If you connecting memory power to EPOWER, expose memory copper plane same way.

STEP 5 - Solder the EPOWER down to the card

Good rule to follow: one pair of wires (VCORE+GND) per each 10-15A of estimated current. For simple VGA with 2-3 phase VRM best to use 4-8 wire pairs. For high-end VGA should be no less than 12-16 wire pairs. Top GPUs like GK200, GM200, GP102 you must use as many pairs as possible physically or solid copper planes.

Solder thick (AWG10-AWG12) wires or 0.5-2mm solid copper plate from EPOWER V GND to ground areas on card and VCC points to power plane. Ground can be probed by DVM in resistance mode, by reading less than 0.1 Ohm between outer metal shells of DVI/HDMI connectors. Use the relative measurement to shorted probes, to null the resistance of the probe leads. If your DMM does not have the relative measurement mode, just short probes together in lowest resistance range and subtract resulting reading later from the actual measurement to obtain true resistance on PCB. Use sharp and clean probes for good contact.

In the end result you may end up with photo next:

Note solid copper connection for the VCORE output between EPOWER and VGA card. Blue AWG8 cable provide additional ground connection. There are more of these wires between EPOWER and the card.

Keep in mind that once you soldered EPOWER on the card, you will lose access to the front side of the reference PCB. This means adding any reworks or modifications in area under EPOWER would be extremely difficult. So add wires and other modifications, like memory mod, power mods BEFORE you solder EPOWER.

After connecting EPOWER V to GPU always check the resistance between power and GND to ensure there are no shorts. Normal resistance range for a GPU is 0.4-10 Ohm depending on GPU, for memory – 10-200 Ohm. If you get very different resistance readings, you card is likely borked and game is over. Well, not really, you just need to find short between power and ground and fix it.

Same process applies to memory power, if you use it from EPOWER. If wires and connections between VCORE and VMEM outputs are too close, check the resistance to make sure there is no short between power rails.

Also I have collection of resistance measurements on legacy graphic cards, listed here.

STEP 6 - Final check and first power on

After obtaining good results on resistance check, you can go ahead with final checks and mounting cooling system on the GPU. Insulate PCB from water condensate by preferred way, same as you would do with normal LN2 session. Keep moisture away from the EPOWER V card and ensure that there is no direct contact with frozen areas on target device.

EPOWER V card also requires airflow under heavy load conditions, get some 80-120mm sized DC fans ready. EPOWER provide two 3-pin FAN connectors, each can provide 3 Amps at +12 V.

Install zombie card into the PCIe slot, make sure no metal parts touching the EPOWER PCBA. Connect PCI-Express power 6-pin/8-pin cables to BOTH EPOWER V card AND videocard. This will provide power and ground to the VGA, as most cards still need to have +12V present for auxiliary circuits and detection logic to work properly. Default startup voltage for EPOWER rails is +0.9 VDC for VCORE and +1.35 V VMEM. Preset voltage levels fit modern GPUs like 980/980Ti/1080/1080Ti/Titans.

Now turn system on, and check all the voltages. If power on voltage is OK and there is no smoke coming out of nowhere. but system does not detect videocard – make sure *PWR_GOOD* signal from onboard VRM controller on videocard is isolated, and it's GPU side is indeed +3.3V. If it's low (0V) GPU will be kept in reset (because onboard power is not used – it’s fault state for it).

EPOWER does a quick self-check every power on, and then automatically switches outputs ON. If everything OK, it will display current output voltages on LED display, like displayed on Image 25.

EPOWER output voltage control

Voltage control is easy and straight-forward. There are six buttons on top right corner of the board, which allow to perform all essential adjustments.

* UP - Increase value by one digit.
* DOWN - Decrease value by one digit
* LEFT - Move cursor 1 position left, highlighted by decimal dot on display.
* RIGHT - Move cursor 1 position right, highlighted by decimal dot on display.
* ENTER - Apply new value to EPOWER output
* RETURN - Reset voltage to 0.9 V / 1.35 V levels.

Both displays are controlled by same buttons, cursor for selected digit will automatically switch once you press LEFT (or RIGHT) in most significant digit of the previous display.
Voltage is applied immediately on ENTER keypress, but return to monitoring mode (when both VCORE and VMEM actual voltages are shown) will occur after few second delay.

Monitoring mode is also indicated by red color for LEDs near EPOWER logo. In setting mode color change to green.

Allowed output voltage range for each rail shown in table below:

These values are valid for the default condition out of the box, measured at the output of the EPOWER V card.

Hardware monitoring options

You can use ProbeIt adapter from EVGA Dark motherboard or Kingpin Edition VGA to your usual multimeter probes, or in case you want to have custom cable connection to your specific meter, you can grab connector separately, for example here from Digikey.com. You will also need these contacts. If you want less pins (for example only 4 to monitor GPU and MEM voltage) you can get needed housings right here .

Pinout for this header follows other EVGA OC targeted projects, and shown in Table 4. All voltage outputs from ProbeIt heaters are protected by onboard fuses to ensure safe probing. Same pin definition legend is printed on the bottom side of the EPOWER board.

Also five white LEDs near the PCBA edge allow to monitor the voltage health in realtime. Their definition and function is same as older Classified/KINGPIN cards. If any of the LEDs not on, the voltage rail is absent and system/EPOWER may require troubleshooting.

Onboard switches to control EVGA EPOWER V settings

Set of three dual-position switches control advanced features, such as fixed voltage offset, VRM protection override and remote sense function.

Top to bottom they are labelled *VOFS*, *FORCE* and *DROOP*. Factory default setting for all switches is *OFF*, with slider position to the right side. Status and function map for all these presented in table below. Different switch functions can also be used in conjunction.

Voltage increase method is bit different to software or onboard EVBOT override control as an offset is applied at any programmed voltage. It could be useful if you wanted test little bit extra voltage for experiment, without changing programmed setting. Each offset VOFS switch position at ON will add +80 mV, so both will give +160 mV.

Second switch, marked green on Image 28 is for protection override, and would rarely be needed for typical LN2 overclocking. If you suspect that power loss occur due to OCP (which is set really high on EPOWER V), you may try to toggle FORCE switch position to ON and back to OFF to attempt a power reset.

Last, but not least *DROOP* switch. Default "OFF+OFF" setting tells controller to regulate voltage to the programmed value right at the EPOWER board, without taking any loading into account. Let's imagine simple example, VCORE programmed to 1000 mV. With this setting EPOWER's VRM controller will continuously monitor output voltage at EPOWER and adjust switching operation of PowIRStages accordingly to get matching 1000 mV. So the whole system forms a closed feedback loop that maintains stable output. This also mean that VRM controller does not "see" the loading, so if there is a voltage drop on connection wires and reference board PCB equal to 100mV, actual GPU core will get only _1000 mV - 100 mV = 900 mV_.

Now middle settings with either of the switches set to ON will add spacing between sense points so there will be some impact from loading current. In same example VRM will sense some of voltage drop due to loading, and will attempt to compensate by overshooting the output voltage. So with programmed 1000mV setting you may get actual 1050mV, as 50mV loss was accounted for. As result _1050 mV - 100 mV = 950 mV_, so GPU will get closer voltage to the setting.

Remote sense option for maximum control over voltage drop

Remote compensation takes this concept to the extreme end, meaning that VRM will ignore onboard voltage at EPOWER and measure the output voltage for compensation at resistors RFP/RFN. Sometimes it is also desired to have fine control over feedback and voltage control under load. To provide best experience with EVGA EPOWER V, flexible remote voltage sense operation is allowed. To fully utilize remote sensing, you need to desolder these two resistors (they are 0 Ohm SMD1206 shorts). Two resistors are installed on the EPOWER PCB by default, just near the bottom left edge.

Top resistor RFP is providing positive (+) signal to the VRM controller (gray pad on photo above), while symmetrical RFN is providing negative return (&minus. To compensate on remote location, connect twisted cable (for example two wires from Cat6 Ethernet cable) and solder them to the points on the reference board attached to EPOWER. Maintain correct polarity, meaning that positive VCORE connection must be connected to RF[*P*] gray pad, and nearest GND return must be connected to RF[*N*] gray pad. As result any voltage droop between EPOWER and sense points would be eliminated by the output overdrive. Sense wire is visible on the Image 24 presented above in this article.

For example, to completely eliminate voltage droop you can route sense wires right to the capacitor + and - pins in area behind GPU on back side.

* Remove RFN and RFP zero ohm (short) resistors
* Solder twisted wire pair to right points (gray pads) of RFN and RFP
* Connect RFP wire to +Vcore on VGA copper plane point
* Connect RFN wire to -GND on VGA copper plane point

Make sure your sense wiring is correct, and right RFP pin is connected to positive sense point on target device (+Vcore). Right *RFN* must be connected to negative sense point on target device (GND). If connection get broken output voltage will be unregulated, which can damage your graphics card or/and EPOWER!

In same example as above math calculation with look like _1100mV - 100 mV = 1000 mV_. This meaning that GPU will have same voltage delivered as the programmed setting. If you connect to different locations +/− on reference PCB, you can get effect somewhat in between, with just medium droop compensation. Experiment on your specific setup to find what gives best overclocking results, as there is no universal rule that match every GPU.

Remote sense function can help to mitigate issues due to smaller/weaker connection between EPOWER and VCORE, but it must be applied with care, as there are limits when compensation cannot work reliably anymore. In typical setups VRM can handle around 250mV maximum of voltage droop between EPOWER and sense point. If actual voltage loss is larger, you must add more wires/copper between boards.

Switches can be adjusted any time and work separately from digital controls, due their hardware function nature.

Firmware update procedure and available firmwares

As EPOWER target audience is usually experienced overclockers, firmware upgrade procedure is available now to provide even greater control on EPOWER functionality. Firmware update workflow shown in list below:

* Connect all three 6-pin PCIe Power plugs from PSU.
* Connect EPOWER interface port USB Type-C to your Windows-computer.
* Extract contents of *firmware .zip* archive to empty directory.
* Run DFUAPP.exe tool. This tool has simple GUI to allow download and uploads of the EPOWER firmware.
* Hold RETURN key and power on the PSU with EPOWER connected.

EPOWER should show *CODE UPD-* message on the LED display, and DFU application should be able to detect connected EPOWER

* Select firmware *.bin* file from the file in Download section.

* Press "Start Download" button to update code in EPOWER with selected binary file.

Now DFU tool will upload the code into EPOWER controller. During the process you will see *CODE UPD-* LED display message flashing, that is expected.

Once completed, you will be greeted with "Download successful" message.
* Unplug USB cable and power cycle the EPOWER.

Available firmware list provided in list below.

* EVGA EPOWER V, Rev.52a firmware, best for GTX 1080/1080Ti/Titan X(Pascal), default 0.9 V / 1.35 V = RAR SFX-archive. Checksum CRC32 is 2DFECD54.
* EVGA EPOWER V, Rev.52b firmware, best for GTX 980/980Ti/Titan (Maxwell), default 1.2 V / 1.5 V = RAR SFX-archive. Checksum CRC32 is 4FB21602.

There are no performance difference between firmwares, it's just default voltage settings.

DFU tool allow any direction upgrade, both from newer version to older, and from older to newer.

Conclusion and feedback

Hope this will help to get better overclocking and world records out of your hardware, with no more power delivery issues or limitations. If you find errors or have issues using your EVGA EPOWER V, feel free to leave a comment here or in discussion thread here.

PDF-version of the guide.

If you have question, please post in public forum. I do not reply PMs, so all in community can benefit the answer. 
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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/11 01:32:06 (permalink)
During pre-EPOWER era, extreme overclockers were known to cut and saw dead VGA cards to salvage VRM for zombies and combining with other cards with weak VRMs. For history sake, I leave this steps guide covering such a feat:

Things needed: 2900 XT/Pro reference design card.
Tools: High-power solder iron (60 to 100W), saw, good to have some sanding tools, multimeter, usual ATX power supply for checks, some wires
Time frame: 1 hour
Complexity: "Easy"


Welcome one of most complex PCB designs in gaming videocards market. Radeon 2900XT PCB with 512-bit memory bus, high-end R600 GPU and state-of-art Volterra VRM. This is what we zombienize today.

This exact patient have crippled GPU, lacks of passives, and memory chips, but fully functional power curcuitry. Perfect candidate for our task.

So for first step - get this card, with working VRM. You can check VRM easily by installing videocard into PC and checking if GPU and memory voltages are present and okay. No more checks needed right now. If voltages are ok - your card is able to be zombie.

Closer look on VRM side:

Two Volterra VT1165MF chips control seven VT1195SF power devices. There is also standalone Volterra VT233TF VRM, for memory I/O's. It's CSP square chip on left upper corner. VRM takes it's power from 8 pin minifit JR connector and 6-pin one.


Now take your favorite saw and do little dirty work.

Cut VRM from videocard, just straight next to memory chips. Do not inhale dust, it is not good for health. Clean up mess after youself.

So you should get this. Take care not to damage components on VRM side.


Now it's needed to fine cut edge of cut, to prevent any interlayer metal shorts. If you skip this step - you will have flames and smoke of shorted circuits, be sure.

This what I saw just after cut.

Then I took handmill tool with hardened edge cutter and milled edge a bit on medium RPMs.

After minute or two milling sides I get acceptable results

PCB cut should be just like this, without interlayer shorts.

You can clearly see complexity of PCB of this high-end video card. It have two core copper planes and five signal layers each side from them! Total twelve layer of copper. For comparison, 8800GTX have twice less. Also this PCB feature buried microvias, which is not actually used even on modern top cards, like GTX480 or GTX580.


Now familiarize yourself with your new creature. Comfort it with some attention.

Links are clickable here.

So we have next stuff there.

Top side

Back side

So master chip U41 (on right side, near FAN connectors) controls six phases to make ex-GPU power. U59 controller is controlling single phase on left, for memory etc. We could use that single-phase for some aux power. It's able to do ~40A current output, with up to 2V range. Main one is rated near 200-220A with same voltage range. Both controllers are addressable by SMBus/I2C interface, they have different address on bus. Empty pads on top - are transient response testing feature, we don't need that for us yet.


Now check if resistance of main power planes is good.

First - +12V inputs. Use your DMM, set on resistance measurement mode, with 200k-2Mohm range. Connect black probe to GND pin, red one to +12V input pins.


>20kohm and raising, as capacitors charges.

NOT normal:

Anything below <10kohm.


Now check outputs

Same principle, DMM set to 200kohm range or similar

Connect black probe to ground pin, same as STEP 5, red one - to VCCP side of output capacitors, or inductor chokes.


Some value in range 10-100kohm, changing as capacitor charges.

NOT normal:

Anything below 100ohm.

Same with memory single-phase output

Notice the range, there is 100ohm burden resistor on this output, so you should have 200ohm DMM range to check this VRM output.

So normal here:

50-100ohm range.

NOT normal:

Everything below 10 ohm.

Also check resistance between outputs, and between +12V. It should not be less then tens of kiloohms there. If it's close to short - find the short and fix it.

If you have question, please post in public forum. I do not reply PMs, so all in community can benefit the answer. 
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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/11 02:05:28 (permalink)
Old version EPOWERs Guide, that was available back in days:
Often overclocking in search if higher performance of computer hardware require increasing operation voltages. In most extreme cases, onboard power regulators is unable to cope with much higher currents and voltages, and as a solution external power modules are used. One of these modules is EVGA EPOWER CLASSIFIED device. It is available for technology enthusiasts with limited DOA warranty.

Basically module is a multi-phase synchronous buck DC-DC convertor which takes +12V input voltage and regulates it down to 0.6-2.0V, providing over 400 Amps of current.
Since different applications may need different output voltages, in this article we will cover four possible ways to adjust voltage on the fly, at any time device is operating.

Board accepts input voltage by standard MiniFit Jr 6-pin connectors, following PCIe VGA power pin definition. Input voltage range is +10.6 to +13.2 VDC, power supply rated input power should be at least 800W.
All three connectors must be used, as different phases taking power from separate connectors. Main power stage train using 14 phases, using IRF DirectFETs. Output voltage provided on exposed PCB copper edge on component side,
and ground return is exposed on bottom side of board. Good ventilation is highly recommended for optimal performance with higher power levels.


All information posted here is hosted just for education purposes and provided AS IS. In no event shall the author, this site, or any other 3rd party, including EVGA be liable for any special, direct, indirect, or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortuous action, arising out of or in connection with the use or performance of information published here.

Using onboard DIP-switch to control EVGA EPOWER CLASSIFIED output voltage (up to 1.65 V)

Adjusting voltage is possible with toggling 4-position switch SW1. It’s located near top right corner of EPOWER board, just near
FAN and EVBOT interface connector. Switch can be adjusted any time, unless voltage setting is overridden by digital setting (from I2C command).

Using variable resistor to control EVGA EPOWER CLASSIFIED output voltage

If you need finer steps than DIP-switch method provide, or require voltage output higher than 1.68V, you can add trim pot resistor to offset voltage setting.
To do so you will need:
  • 1 kOhm multi-turn variable resistor, such as 3296 size 3-terminal resistor
  • Soldering iron
  • Small piece of insulated wire
  • Multimeter

You can use also 500 ohm or 2K resistor, if don’t have exact 1K.
First remove solder mask in bottom right corner, like shown on photo below. This will be our ground connection spot.
Then measure resistor middle terminal and adjust resistor for maximum resistance. In our case it was 984 ohm.

Now connect middle terminal with small wire to capacitor left side, like shown.

Check all connections and make sure nothing else got shorted.

Original stock condition (shown on photo at left side) have 0.9V as default settings (all VID switches off) and resistance to ground on capacitor terminal reads near 100 ohms. To properly measure resistance, output is required to be shorted
or connected to low-resistance load, as this is part of feedback network. In our case 0.1 ohm resistor was used as a load.
Added trim resistor reduced resistance to 74.5 ohm, which raised output voltage ~300mV, resulting 1.200 VDC. Pay attention as you still can set voltages by VID switch or digitally, but now your output voltage will be with positive offset 300mV. So if you set 1.630V by switch, you will get now 1.930V or about that.

Using EVGA EVBOT to control EVGA EPOWER CLASSIFIED output voltage (up to 1.85 V)

If you happen to have EVBOT controller, you can use it to adjust output voltage by simply connecting to 5-pin digital port at EPOWER. You will need EVGA EPOWER V25 firmware flashed to your EVBOT.
Flashing can be done by either EVGA motherboard (with EVBOT port, such as X58,X79,P67,Z68 series), of EVGA VGA card (Classified and K|NGP|N series cards) utility.
  • Connect the EVBot cable to the MB port located on the EVBot device.
  • Connect the other end of the EVBot cable to your graphics card.
  • Extract contents of above .zip file and run EVBotFlashTool.exe
  • Select the .hex file for flashing.
  • Hold down the EVBot POWER button for 7 seconds until you see the EVBot screen display FLASH MODE.
  • Click OK in EVBot Flash Tool to being the flashing process.
  • After flash is complete, unplug EVBot, then plug it back in to any EVBot port.
This can be done using one of next VGA cards:
  • EVGA GeForce GTX 285 Classified
  • EVGA GeForce GTX 580 Classified
  • EVGA GeForce GTX 680 Classified
  • EVGA GeForce GTX 770 Classified
  • EVGA GeForce GTX 780 Classified
  • EVGA GeForce GTX 780Ti Classified (both normal and KPE)
  • EVGA GeForce GTX 980 Classified (both normal and KPE)
  • EVGA GeForce GTX 980Ti Classified (both normal and KPE)
  • EVGA GeForce GTX 1080 Classified

Using Raspberry Pi to control EVGA EPOWER CLASSIFIED output voltage

You can use widely available RPI to talk with voltage regulator controller on EPOWER via I2C bus. EPOWER CLASSIFIED is using CHIL CHL8318 PWM controller, which accepts VID override digitally from PMBus.
Product brief for CHL8318 describe it as:
  • 8-phase digital synchronous buck controller for core regulation of high-performance INTEL® VR11.1 and VR11.0 platforms.
  • Fully compliant with VR11.1 including PSI and for improved light load efficiency and accurate current output (IMON).
  • Customized Digital Overclocking Features
  • Easy-to-use SMBus Gamer command
  • Gamer VID control up to 2.3V, Gamer Vmax,VID Override or Track, Digital Load-Line Adjust,Gamer OC/OVP, Gamer OFF pin, Gamer OTP
Gamer VID it is, that’s the function which we will use.
Due to safety reasons, we will cap maximum output voltage to 2V, as most modern VGA cards have capacitors on Vcore rated only up to 2V.
Solid capacitors may have nasty explosions and fire if overvoltage happens.
To get started connect your Raspberry Pi I2C interface to EVGA EPower
EVBOT Pinout and connection map is shown in table below:
Raspberry Pi signal nameRaspberry Pi PinEVBOT PinGroundPin 9 on header P1Pin 6 on header J3501I2C Data, SDAPin 3 on header P1Pin 5 on header J3501I2C Clock, SCLPin 5 on header P1Pin 3 on header J3501
EVBOT Pinout is next (looking at connector’s face):
Pin 1 Pin 3 SCLPin 4Pin 5 SDAPin 6 GND

Now you can power everything on, and connect to Raspberry Pi terminal.
Download next tool and put into Pi’s disk storage.
ELF-executable for Raspberry Pi Linux [using I2C1 port]
ELF-executable for Raspberry Pi Linux [using I2C0 port]
This little voltage setting tool was compiled and tested on Raspberry Pi B v2.0, running wheezy image.
/repo/epower# uname -a
Linux tin.pi 3.12.35+ #730 PREEMPT Fri Dec 19 18:31:24 GMT 2014 armv6l GNU/Linux
/repo/epower# /opt/vc/bin/vcgencmd version
Dec 19 2014 18:44:06
Copyright (c) 2012 Broadcom
version 5abd572e2ed1811283443387af09377b95501c50 (clean) (release)

Select correct version for either I2C0 port (it need modify your Pi to add header for it), or default I2C1 port, available on main header at pins 3 and 5.
Tool requires wiringPi library installed, with i2c enabled.
If EPOWER cannot be detected, tool will issue error and exit, like below:
%{color: blue}/***** EVGA EPOWER CLASSIFIED Manual VID setting tool ************/%
%{background: #f00; color:yellow}/!\ ERROR : No valid I2C0 device found, aborting..%

Or in case of I2C1 version:
%{color: blue}/***** EVGA EPOWER CLASSIFIED Manual VID setting tool ************/%
%{background: #f00; color:yellow}/!\ ERROR : No valid I2C1 device found, aborting..%

If that happens, check that I2C bus is accessible, and all connection between Pi and EPOWER is correct.
Using i2c-tools i2cdetect with proper connection should give you present devices on address 0×0C and 0×46.
/home/pi# i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- 0c -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- 46 -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

After everything successfully detected, you can run software tool:

Here voltages in 100mV steps were entered, and actual readout values for input, output voltages and temperature was reported.
If user enter zero value into desired voltage request – tool will switch to monitoring mode, which will report current settings in infinite loop.
This could be handy to see if some protection, like OCP/OVP shutdowns output voltage during benching session.
Hope this will help to get higher overclocks and records out of your hardware.


First, we need to prepare tools and items needed to install

1. VGA card itself. Now it's 8600GT 256MB
2. EVGA The Untouchables EPOWER version 0.1 (10+3 phase)
3. EVGA EVBot for voltage control
4. Bunch of LowESR tantalum and electrolytic capacitors
5. Thick copper AWG12 wire in teflon insulation
6. Soldering tools , 50-100W optimal for thick wire soldering.
7. Cooling colution, I will use newest Kingpincooling.com Tek9 FAT 6.0 here
8. Digital multimeter, any generic will fit ok (I will use Keithley 2001, just because I have it )
9. Cup of tea to encourage yourself
10. Small usual tools like screwdrivers, cutters, etc.


Now take a look on videocards and find big beffy inductors of stock VRM curcuitry. To connect external power supply to card we need to disconnect onboard one first.
This can be easy done by desoldering original inductors. On 8600GT it's just single phase DC/DC's so one inductor per each VRM, one for memory, one for GPU.
On next photo I show already removed chockes. Big black one is from GPU VRM, smaller - from memory VRM.
You can clearly see that one side of choke go to VRM mosfets by big polygon (big solid copper area) and second go to output capacitors and furter go internal layers to GPU.
Our idea - to connect external power to this output capacitor polygon, thus having power flow into original power planes from external source.


But first we need to find placement for EVGA "The Untouchables". Connections between VRM card and videocard must be as short as possible.
That's because of usual ohm law - higher resistance on line with high current flow cause voltage drop. So if we decrease resisance - voltage drop will be reduces.
With low-power GPU's like lowend and middle cards it's not that critical, but even now current between VRM and GPU can reach impressive 20-50 AMPs because of
relatively low voltage needed by GPU/memory. So find area where future VRM will be fixed, having in mind to keep path to onboard VGA power curcuitry shortest.

I decided to hook EPOWER on back of card. Why, you ask? Because front area will be covered by big cooler, but back one is free and have nice areas for soldering.
The only problem is card installed in motherboard, it must not block CPU cooler or other motherboard heatsinks in system. So check triple times before you solder VRM on!
I'm using F1 Gemini LN2 container on CPU, and did not spend enough time checking placement, so my assembled system will look very tight

Now important part. We found polygons of original VRM outputs, and now need to remove protective mask ink from PCB surface to have soldering access to copper. You can use any tool suitable for scratching etc, I used my trusty Proxxon with sandpaper cylinder on it. Some shhrrr-shhrrr and job done as on picture.Take care not to nake or short any other vias or traces on PCB, or you will need to repair broken connections. Also don't push too much force, coz copper layer is thin (35-70 micrometers often!)

After than check if card still ok, by measuring resistance on planes. Should not be shorted to <0.5 ohm resistance to ground. My 8600GT still ok, shows 2.88ish ohm on GPU
and 74.76 ohm on memory.

Remember these values, we should always check them before powering, to ensure there is no shorts somewhere.

Now we are ready to connect Untouchables to card itself. This will be done by short AWG12 wires. Solder wires on each plane, keeping symmetric connection to ground return too.
So if you soldered two wires for GPU power - solder two same wires to ground return. Current flow is not from one point to another, but is like endless flow by circle, from output to ground input.
Keeping shortest possible path for this current - is key to have lowest resistance value and reduce voltage drops.
General rule here - connect as much wires as possible, but keep in mind usability of final assembly.
Also solder joints must have enough solder to fix everything firm. Check shorts and solder balls on other components, avoid that.

Soldered now. From now better not to put force or stress on cards, because if you push too much - fragile polygons with heavy wires soldered on can be easily damaged.
On pic you can see two wires connected to each VRM section. Ground wires (4) are connected under The Untouchable.

Almost ready, time to add some extra capacitors.

And check some resistance. Should about same values we got on steps 5 and 6. If you have close to zero - somewhere you shorted power to ground. Remove short and redo measurement again.

Don't forget to check memory resistance too!

Now take cup of tea and relax, looking on abomination you created here. Now you can scary any normal human by showing what you have done with poor videocard.
Oh, I went some offtopic..

As for capacitors - use LowESR caps with suitable power rating (I usually use 2.5V for GPU and 6.3V for memory parts).
Connect them in right polarity to points on card, where you connected wires. Capacitors will help to smooth power drops under transients.
I always add some capacitance under GPU on back of PCB as well, on this point voltage drop is most critical, but also hard to reduce because of higher frequency.
So better use MLCC or good tantalum caps under GPU's, if you can fit them. Avoid long legs on caps or any kind of wires here, adding wires would not help anything.

You can also see that I added short ground wire for GPU VRM portion. Also usually good idea to add some bulk electrolytic cap on far end of memory power plane. You can easy
find points of memory power by checking resistance on surrounding MLCC ceramic capacitors.

Now check resistance of final zombie (tired , yea? ), and if everything ok -> mount your insane Kingpincooling container to GPU and assemble evil thingy to your system.
I will use 2600K and P67 FTW here. Don't forget to connect EVGA EVBot to port on "The Untouchables" EPOWER.

Everything seems ok, raised voltage from EVBOT on memory to 1913mV idle. On EVBOT you must use MB channel. CPU Voltage will be representing main VRM channel on EPOWER, DIMM Voltage - extra 3-phase output control. Ignore everything rest.

Now after everything booted and working ok - do your usual stuff, adjust voltages to desired levels, bring temperatures down, and perform your best on overclocking. And take measurements of voltages directly on videocard, not on epower card. Because we have now noticeable voltage drop, so on this 8600GT lowend card setting 1.5V on EPOWER will get 1.42-1.45V on 3Dmark03, so to get real 1.5V you will need to set 1.55-1.57V on EPOWER. On heavy cards, like GTX 590 this got really serious, with 12+ wires connected between power card and videocard there was big drop, what needed 1.7V on EPOWER to get 1.3-1.35V on load on GF110 GPU. So benefit is major from EPOWERs on lowend/middle-end cards, because then don't eat as much current, so EPOWER will do best on cases where strong VRM limitation exist. Only EPOWER allowed me to overclock GTX590 to more than 1100MHz on GPU's, while all normal overclockers stopped on futile 800-900MHz at best.

If you have question, please post in public forum. I do not reply PMs, so all in community can benefit the answer. 
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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/11 04:38:10 (permalink)
I have two of theee ready to rock on a GPU that I just received and is sacrificial to learning experiences.

Are the EPOWER boards reusable, if the connections are severed GPU side, as long as the EPOWER board isn’t damaged?

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/11 04:57:26 (permalink)
Yes, if you carefully remove the connections between EPOWER and target device, there is no problem to reattach it later to another card. I did that multiple times, and with copper plates and high-power soldering iron with wide chisel tip it takes 10-15 minutes to attach/deattach EPOWER. Most time you spend cutting plates/wires and forming them to fit into GND/VCC shapes ;).
I think most benefit of EPOWER would be visible running on older cards, especially reference designs which used to be cost-down a lot with phases removed/etc. Modern GPUs like 1080+ already have rather good VRMs. Feel free to ask if you have specific questions.

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/11 05:12:45 (permalink)
I have a 980 that had a section of the PCB burn out near the end of the card, and I am just wanting to see if so can bring it back and get it slightly functional with the EPOWER :-D

It is a reference PCB, and I am just wanting to learn. I have a cheap soldering iron, and will be picking up a much better iron to work on this, as I want to do it the correct way.

If I am get it functioning again, I will pick up some pots and try to get back into overclocking.

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/12 19:11:25 (permalink)
Very Interesting, seeing this detailed how to
RE:  "mill to clean the edge of the cut card to remove cross layer shorts" --> Would sanding (belt sander) work if a mill is not handy ?

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/12 20:31:12 (permalink)
Scarlet, that may work, just be sure to remove all charred material and confirm there is no dead shorts between any of the damaged copper plates/traces.
Cool GTX, yes, even manual file or sandpaper block would work, point is to make exposed copper layers on the edge clean and smooth, not shorting each other. Because internal power planes are like sandwich : SIGNAL - GND - POWER - GND - POWER  - GND - SIGNAL.
You do not want power dead short to ground or some signals ;)

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/12 20:43:12 (permalink)
Here is yet another guide section, covering GTX 780 Ti + EPOWER CLASSIFIED (red one).
New EVGA E-POWER "The Untouchables" CLASSIFIED

One of most successful cards for using with zombie power was GTX 680. Relatively low power consumption and high performance was playing good together with added complexity of using external VRM. Desprite of voltage droop and not optimal current path that combo was still able to impress overclocking community by delivering over 1900MHz GPU clocks stable enough to break records in heavy 3D'11 benchmark. But now, with GK110 big brother we can say bye-bye to low power consumption. 7 billion of tiny mosfets dying from hunger, and we need to satisfy their needs if we want to get decent scores from card.
But in real world overclocking is not most important thing, so reference TITAN and GTX 780 are just good enough for their stock clocks and voltages, but nothing above. Few brave guys tried to prove that wrong, but were quickly taught 1000$ USD lesson of fried electronics.

So I had a clear task in front of me - we need some real stuff, something that can hold TITAN-class power dreadnought like a toy.
And using experience we gained on GTX 580/680 CLASSIFIED designs, and my own observations on zombified GTX 580, GTX 590, GTX 680, GTX 690 with our good but now obsoleted 10-phase Volterra-based Untouchable I came up with digital-based IR VRM with 14-phases, just as our 680 CLASSIFIED VRM minus memory power and VGA-related stuff.
As I show later, I wanted to include few nice and useful features to make usage easier and better power delivery.

Since today, wait is over, now everyone who is capable to hold soldering iron and have balls to loose warranty for their VGA forever - now can have key component of CLASSIFIED-branded EVGA graphics card on their own VGA, any model, any vendor, any color, even ATI

Lets take a look, and go thru process of zombifying brand-new fresh NVIDIA GeForce GTX 780 I have here on my desk.

That's overview of everything important we will need today:

* Any vendor VGA card
* EVGA EVBOT for voltage adjustments
* 80-150W soldering iron (need lot of beef to solder on power planes, due to good thermal dissipation. Your 25W SMD iron will NOT WORK)
* Soldering FLUX
* Heavy-duty cutters for metal
* Copper pads/plates (1-2mm thickness is best, still easy to bend, and nice low resistance connection)
* Kingpincooling TEK9 FAT (don't forget who's forum is here, yes
* DMM (I use Fluke 87V and Keithley 2001, but any DMM can fit this needs)
* Low-ESR capacitors (2.5 or 4V rated, 680-820uF , etc)
* Some VRs for regular vmods for memory, PLL, etc (not shown on photo)

Pretty standard list, only new thing - copper plates. I found them better than crazy wires because they are not flexible (can fix position and then solder it firmly easier), have lower resistance, and easy to reuse. Also no burning wire insulation and nasty smoke, which is healthier for overclocker :P

I buy these at local PC cooling parts shop, but pretty sure those are not hard to get all over the world in some metalwork shops, etc.


Get rid of fancy heatsink, chop off goofy VRM from our GK110 by removing 6 power inductors.

There coils are easy to remove with 150W iron, just heat one side up and lift it.
Then desolder second side and remove a choke.


Do your memory voltage mods, or anything you want on VRM PCB area. Don't repeat stupid TiN mistake, who connected EPOWER and realize after all work alredy done that there was no memory mod done, and that area under EPOWER have no access now.


Cut a magic trace and say BYE-BYE to your GTX 780/TITAN warranty. Who need that stuff anyway, right?

Don't try to be smarter, there is no other resistor/component/way, other than cutting trace. If you don't agree - ok, write your own guide then


When using external VRM the bottleneck is always interconnect between target board-victim and power source board. That is why no connectors can be used to make "customizable" EPOWERed VGA, or "configurable" VRM. When you think about currents (hundreds of AMPs) and voltages (less than 2V most of time) and required regulation tolerances (<1% most time), there is no way that even big power connectors will be good enough to meet those specs.

I mean, yes, some vendors do have product which allow external VRM to be user-connected by some interface connector, but none of those products received any performance records or gains from such marketed "improvements". Same goes to extra addon boards with capacitors .

So the only answer and option is DIRECT connection with solder, PCB to PCB, with shortest path and widest plane possible.
As a result new EPOWER CLASSIFIED allow you to connect power output to VGA not only by one outer copper layer, but by 4 layers, including 3 interals layers.

To use this option you will need to cut edge of EPOWER card (around 5mm from edge, by start of vias and VCC EDGE marks in PCB).
After doing so - you will see three extra power copper layers exposed on edge. Then do SHHRRR-SHHHRRR on edge to make it smooth and flat and use solder to interconnect everything together. In terms of marketing there is 400% improvement, but we are serious guys here, so let's just say it's better


Now let's align EPOWER and VGA together, get coffee/tea/vodka and think a little, how we want to connect both boards together
and minimize current path. You can locate EPOWER from back side, top side, whatever side you think good for your use, it's really up to you. But in this guide and this particular card my target was next:

* Shortest and widest connection
* 4-way SLI-capable spacing
* Easy access to EPOWER for debug

So this gives only one position - in front of card, with minimum angle to PCB.It's bad position from ground power plane delivery POV, so I'll need to find alternative way to connect grounds, but it still should be good enough. If I would need ultimate single GPU style card - I would connect EPOWER under 90° angle to VGA with direct connect of both VCC and GND planes. New EPOWER CLASSIFIED have VCC OUT copper plane area exposed on top layer (one which have components/heatink on it) and GND plane exposed on bottom layer.




No comments required. Be careful not to shhhrrr non-power traces/vias :P


I wanted to lift power plane above PCB surface, so i can directly solder EPOWER edge to it. To do so I made 4-6mm thick copper clads and solder them with LOTS of solder on GPU power plane on VGA.

Don't confuse power with ground. DMM checks on every operation here are essential, to make sure that VCC is still VCC, and GND is not shorted to it. Good idea to solder DMM probes to VCC and GND so you can monitor resistance non stop. There is small caveat here, when PCB is hot from soldering - resistance will drift away. Fluke 87V can show negative resitance with this , like -1.5 ohms for example Don't get fooled, it's delta you are looking for, not some specific value.


Now need to bend shaped copper plates to have nice and robust connection between PCBs. It's more like half-hour of metal bending, aligning, fitting, bending, fitting, bending, bending, getting angry, bending, bending, saying bad words, bending, fitting... and only then soldering perfectly matched bent copper plates together, making EPOWER and VGA one solid common thing - called Untouchable.

Here's VCC soldered on front:

Now GND on back

Support GND "leg"

One way to connect GND on front (card on right side)

Another way to connect GND by copper plates connecting capacitor grounds on top with copper GND "wall" between VGA caps and memory IC's.


Now look on abomination monster which you have just created. Like it? Want to break record with it?  Not so quick, fella! Check your resistances before you put it into system and blow everything apart.

Healthy GK110 GPU usually have ~2-4 ohms. If you have less than 1 ohm - time to find short and go thru all pain of redoing everything again from step 1, but now worse - because you forgot to follow TiN's suggestion on step seven and need to remove all copper soldering from zombie. It's harder than putting on, believe me, i went thru this

Healthy mems are around 20-30 ohms for Titan, and 40-70 ohms for 780 (because twice less memory IC's)

Healthy PLL rail resistance is around 100-200 ohms.


Now, after all hardware is good, you can relax a bit, get grease, insulation stuff, best pot in the world, TEK9 FAT 6.66, and start putting
everything together for benching.

Apply vaseline

Melt it.

With pot

And then - it's ALIVE

Don't pay attention to oscilloscope in background, it just there to make "scientific look", nothing else, believe me
Enjoy benching.
Now repeat guide above 4 times, just like this:

Chopping off inductors

Pre-testing cards with TEK9 SLIM

Thin design capable of fitting multi-GPU

They are ready to show us some results.

post edited by TiN_EE - 2019/02/12 21:00:33

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/02/21 09:50:15 (permalink)
Hay are you going to make the software toolkit/software to control it over USB. available as the link that comes with the Epower V is dead along with the Kingpincooling.forums
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Re: EVGA EPOWER V - User's guide and installation tips. 2019/06/05 09:49:36 (permalink)
User whiteshark on the r/overclocking discord server put together an awesome PDF with instructions detailing how use serial to to get software control.
EDIT: Just realized I currently do not meet the requirements to post the link to it, it's in the #mod-reference channel of the /r/overclocking discord server.
post edited by Rave - 2019/06/05 09:53:03

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Re: EVGA EPOWER V - User's guide and installation tips. 2019/06/06 03:51:27 (permalink)
Uploaded PDF-tutorial about using serial console for EPOWER V from 1whiteshark1 @ hwbot.
post edited by TiN_EE - 2019/06/09 18:16:01

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