xitywampas
1: Corsair CP-9020087-NA is a single rail PSU.

2: All of the connections will draw power. Unless the circuit is opened it will draw power. Current draw will not be exactly even but will spread out across the circuit depending on individual resistance per connection. One connection will have a higher draw because the connections are not perfect and will have variation. In other words, the current will take the path of least resistance. My card shows port 2 as the high power draw as it probably has the least resistance to flow. I take these and any software numbers generated inside the OS with a grain of salt.

3. Software measuring will never be %100 accurate. If you want to see this accurately it must be an inline measurement system or an inductive one running independently of the system being measured. Everything else should be considered marginally accurate at best.

AnonymousGuy
Here's my guess: 3 of the 8 pins are probably always connected to the voltage regulators.  It's completely possible that one of those pins takes most of the load at idle (the AXi series current monitoring doesn't work below 3A or so, so it may show "0") and then the other 8+8 takes more as the voltage regulator ramps up.  There is no "switching" of the connectors on/off.
 
There's no way of knowing or conclusively saying that all 3 are always balance...unless you know how the power planes are set up.  They're not always connected on the PCB.  You could simply try running the card with 2x8 pins and seeing if it's "OK"...it probably would be.

AnonymousGuy

jankerson

AnonymousGuy
Here's my guess: 3 of the 8 pins are probably always connected to the voltage regulators.  It's completely possible that one of those pins takes most of the load at idle (the AXi series current monitoring doesn't work below 3A or so, so it may show "0") and then the other 8+8 takes more as the voltage regulator ramps up.  There is no "switching" of the connectors on/off.
 
There's no way of knowing or conclusively saying that all 3 are always balance...unless you know how the power planes are set up.  They're not always connected on the PCB.  You could simply try running the card with 2x8 pins and seeing if it's "OK"...it probably would be.

 
Yeah, exactly, about the AXI.
 
I did actually pull one of the 8 Pins and it won't even start so all 3 have to be connected for it to run.

I believe that's a software BIOS thing with the sense pins on the connector.  I think you could ground the sense pin on the connector and see if it actually boots up still?

jankerson

xitywampas
1: Corsair CP-9020087-NA is a single rail PSU.

2: All of the connections will draw power. Unless the circuit is opened it will draw power. Current draw will not be exactly even but will spread out across the circuit depending on individual resistance per connection. One connection will have a higher draw because the connections are not perfect and will have variation. In other words, the current will take the path of least resistance. My card shows port 2 as the high power draw as it probably has the least resistance to flow. I take these and any software numbers generated inside the OS with a grain of salt.

3. Software measuring will never be %100 accurate. If you want to see this accurately it must be an inline measurement system or an inductive one running independently of the system being measured. Everything else should be considered marginally accurate at best.

 
All modern PSUs are single rail.
 
It's some have Multi-Rail OCP so they are called Multi-Rail today. The correct term is Multi-Rail OCP, being technical about it.
 
Now some are Single Rail/Multi-Rail switchable either by a physical Switch or by software by direct hardware connection to communicate with the PSU.
 
Back in the day they used to be real hardware multi-rails though. But that was when everything really ran off the 5V and 3.3V and the 12V wasn't used really.
 
Everything runs off the 12V+ today, all the big power draw parts like the CPU/MB and Graphics card. The 5V and 3.3V are still used, but they aren't as relevant as they used to be.
 
 
 
 
 
 
 
 

xitywampas

jankerson

xitywampas
1: Corsair CP-9020087-NA is a single rail PSU.

2: All of the connections will draw power. Unless the circuit is opened it will draw power. Current draw will not be exactly even but will spread out across the circuit depending on individual resistance per connection. One connection will have a higher draw because the connections are not perfect and will have variation. In other words, the current will take the path of least resistance. My card shows port 2 as the high power draw as it probably has the least resistance to flow. I take these and any software numbers generated inside the OS with a grain of salt.

3. Software measuring will never be %100 accurate. If you want to see this accurately it must be an inline measurement system or an inductive one running independently of the system being measured. Everything else should be considered marginally accurate at best.

 
All modern PSUs are single rail.
 
It's some have Multi-Rail OCP so they are called Multi-Rail today. The correct term is Multi-Rail OCP, being technical about it.
 
Now some are Single Rail/Multi-Rail switchable either by a physical Switch or by software by direct hardware connection to communicate with the PSU.
 
Back in the day they used to be real hardware multi-rails though. But that was when everything really ran off the 5V and 3.3V and the 12V wasn't used really.
 
Everything runs off the 12V+ today, all the big power draw parts like the CPU/MB and Graphics card. The 5V and 3.3V are still used, but they aren't as relevant as they used to be.
 
 
 
 
 
 
 
 

I don't think all PSU are single rail but I know most are. I still have a couple of true multi-rail PSUs laying around, but yes you are correct about that. The ones I have are over 10 years old.