Iluv2raceit

Sajin

"Virtually Silent Operation, Variable controlled fans allow dynamic fan speed based on gpu temperature, and the water cooling efficiency means very low fan noise."
 
Source: https://www.evga.com/prod...aspx?pn=400-HY-5388-B1

Unfortunately, the reality is that the fan does not run silent, nor anywhere near it.  The 2-pin solution to split off the PWM fan header on the card's PCB doesn't work as well as one might hope.  I used my own solution for my SC2 Hybrid:
 
1) Removed EVGA's 2-pin fan and replaced it with a Noctua SSO2 120mm 4-pin PWM high static pressure radiator fan:
https://www.amazon.com/gp/product/B00KFCR5BA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
 
2) Plugged the Noctua fan into a PWM fan header on the motherboard
 
3) Installed an Uxcell TC 2-pin Temp sensor onto the motherboard and the probe was placed onto the exterior of the radiator to measure the air exhaust temperature:
https://www.amazon.com/gp/product/B01DDH68CK/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
 
4) Using the Asus software suite, I created a custom fan curve for the fan header on the motherboard controlling the Noctua fan and selected the Uxcell TC as the source for the temperature monitoring; I used several high load GPU benchmarks to determine the range of the radiator exhaust air temperatures and adjusted the custom fan curve accordingly
 
Temps and fan noise are lower now vs. the stock configuration

HeavyHemi

Sajin

HeavyHemi

Sajin

nycalex80
i thought the radiator fan was 100% power 100% of the time?

It's dynamic based on coolant temp.

Pretty sure the radiator fan is static fixed 12v.  It's a two wire fan no PWM.

"Virtually Silent Operation, Variable controlled fans allow dynamic fan speed based on gpu temperature, and the water cooling efficiency means very low fan noise."
 
Source: https://www.evga.com/prod...aspx?pn=400-HY-5388-B1

It certainly does say that.  However, the fan is a two wire fan. Thus there cannot be any PWM control of the fan. The voltage is fixed at 12v just like it is for the pump. So, EVGA needs to correct their information.
 
From EVGA Tech Erin:
The radiator and pump operate at a fixed speed. The four pins on the fan header are tach, PWM control, +12V, and ground. The pump and radiator tap power from the +12V fan power feed from the card. Only the fan on the card itself is variable, as it has the connections to the PWM control signal. The +12V is constant, and doesn't change.

If your radiator fan is changing speed, it's not doing so in response to the temperature.

then what could it be?
 
what could be slowing down my noctua fan?

HeavyHemi

Sajin

HeavyHemi

Sajin

nycalex80
i thought the radiator fan was 100% power 100% of the time?

It's dynamic based on coolant temp.

Pretty sure the radiator fan is static fixed 12v.  It's a two wire fan no PWM.

"Virtually Silent Operation, Variable controlled fans allow dynamic fan speed based on gpu temperature, and the water cooling efficiency means very low fan noise."
 
Source: https://www.evga.com/prod...aspx?pn=400-HY-5388-B1

It certainly does say that.  However, the fan is a two wire fan. Thus there cannot be any PWM control of the fan. The voltage is fixed at 12v just like it is for the pump. So, EVGA needs to correct their information.
 
From EVGA Tech Erin:
The radiator and pump operate at a fixed speed. The four pins on the fan header are tach, PWM control, +12V, and ground. The pump and radiator tap power from the +12V fan power feed from the card. Only the fan on the card itself is variable, as it has the connections to the PWM control signal. The +12V is constant, and doesn't change.

If your radiator fan is changing speed, it's not doing so in response to the temperature.

Guess the techs don't know what they are talking about. https://forums.evga.com/FindPost/2672386

HeavyHemi
I agree over the years we've seen the techs make mistakes. They are human.  However there is no disputing there is no PWM control on a 2 wire fan. So, they really should get their ducks in row.

I've seen people say the radiator fan adjusts. I've also seen people say it doesn't.

HeavyHemi

Sajin

HeavyHemi
I agree over the years we've seen the techs make mistakes. They are human.  However there is no disputing there is no PWM control on a 2 wire fan. So, they really should get their ducks in row.

I've seen people say the radiator fan adjusts. I've also seen people say it doesn't.

I'm sure you have. It's a two wire fan. Thus no PWM control. Do you accept that as true?

Yes, I agree there is no pwm control on a two wire fan. Fan speed can still be adjusted on a two wire fan.

HeavyHemi

Sajin

HeavyHemi

Sajin

HeavyHemi
I agree over the years we've seen the techs make mistakes. They are human.  However there is no disputing there is no PWM control on a 2 wire fan. So, they really should get their ducks in row.

I've seen people say the radiator fan adjusts. I've also seen people say it doesn't.

I'm sure you have. It's a two wire fan. Thus no PWM control. Do you accept that as true?

Yes, I agree there is no pwm control on a two wire fan. Fan speed can still be adjusted on a two wire fan.

 
Indeed. However, there is no DC fan controller on the board. So, that leaves us with static fan speed.

They will never admit it.  The funniest description I've seen so far was something like - it does change speed but it's so slight you might not be able to notice it.  I have no idea why they won't say it's static.  I'm guessing at some point they said it was variable in marketing material and won't change their stance because of possible legalities.  I'm happy either way knowing it's a static speed.  I just hate it when people ask and are sent on a wild goose chase.  The way it's wired it shouldn't be changing speeds period.   A PWM fan of course can run into speed issues because they require a signal wire to tell it what to do... without that signal it seems It's putting nycalex80 fan into a constant Min/Max cycle awaiting a command from the controller, but lacks a signal.

Listen folks, just use my solution (on page 1 of this thread) and no more worries ;-)