Why does voltage drop on 12v rail when card folding

[iokeith]

I installed TechPower GPU-Z on an XC885 i5-8400 220w PSU machine with a GT 1030 and found the PCIe 16x slot voltage when folding at 1.9v @25w with PerfCap Voltage flag raised, while when idle the rail is at 10.5v @12w. This suggests the card is overloading the rail, yet it has been producing work units and clocking up 150k-200k PPD for some time, compared with about 40K PPD without the card.

GPU Clock [MHz].........................1721.0.....139.0
Memory Clock [MHz].....................1502.0.....202.5
GPU Temperature [°C]...................55.0 .......39.0
Fan Speed (%) [%]........................ 45..........37
Fan Speed (RPM) [RPM...................2250.......1911
Memory Used [MB]....................... 188.........135
GPU Load [%]..............................79..........0
Memory Controller Load [%].............20...........9
Video Engine Load [%]....................0............0
Bus Interface Load [%]...................21...........0
Board Power Draw [W]...................25.8 ........12.5
PCIe Slot Power [W]..................... 25.8 ........12.4
PCIe Slot Voltage [V].....................1.9...........10.4
Power Consumption (%) [% TDP]........0.0...........0.0
PerfCap Reason []........................4.............16
GPU Voltage [V........................... 1.0620.......0.6750
CPU Temperature [°C]..................50.0..........49.0
System Memory Used [MB].............3380..........3151

I noticed that a GT 1030 also has the same affect on the PC x16 12v rail in another machine with 290w PSU, while the 12v rail for the PCIe x16 (wired as x4 slot) for a 60w GTX 1060 drops only 0.2v from 12.1v whether idling or folding. Is this behaviour normal, or any explanation of what is going on please.
Thanks

[chabgood]

Because the card is doing work.

[psaam0001]

That may be something that would have me looking to upgrade to a higher capacity power supply.

In my Core2 Fedora system, and Ryzen 3 Windows 10 system, I'm using 450 watt power supplies in each.

I'm likely going to have to upgrade the one in my Dell T105 from the 300-305 watt power supply that came with it, to a 450 watt soon.

Multiple PCIe GPU's on a single system will need additional power. Especially if they draw more than what the slot provides from the motherboard.

Paul

[aetch]

Have you checked the voltage supply to the card using a multi-meter?

[psaam0001]

Have you checked the voltage supply to the card using a multi-meter?

If that question was for me, the answer is no. I'm not able to run anything like a GTX or RTX series (I only have 2x PCIe x8, and 1x PCIe x1 slots in that T105). It's just a matter of time before the OEM P/S outputs its last watts.

However, it is a logical thing to check.

Paul

[MeeLee]

I installed TechPower GPU-Z on an XC885 i5-8400 220w PSU machine with a GT 1030 and found the PCIe 16x slot voltage when folding at 1.9v @25w with PerfCap Voltage flag raised, while when idle the rail is at 10.5v @12w. This suggests the card is overloading the rail, yet it has been producing work units and clocking up 150k-200k PPD for some time, compared with about 40K PPD without the card.

GPU Clock [MHz].........................1721.0.....139.0
Memory Clock [MHz].....................1502.0.....202.5
GPU Temperature [°C]...................55.0 .......39.0
Fan Speed (%) [%]........................ 45..........37
Fan Speed (RPM) [RPM...................2250.......1911
Memory Used [MB]....................... 188.........135
GPU Load [%]..............................79..........0
Memory Controller Load [%].............20...........9
Video Engine Load [%]....................0............0
Bus Interface Load [%]...................21...........0
Board Power Draw [W]...................25.8 ........12.5
PCIe Slot Power [W]..................... 25.8 ........12.4
PCIe Slot Voltage [V].....................1.9...........10.4
Power Consumption (%) [% TDP]........0.0...........0.0
PerfCap Reason []........................4.............16
GPU Voltage [V........................... 1.0620.......0.6750
CPU Temperature [°C]..................50.0..........49.0
System Memory Used [MB].............3380..........3151

I noticed that a GT 1030 also has the same affect on the PC x16 12v rail in another machine with 290w PSU, while the 12v rail for the PCIe x16 (wired as x4 slot) for a 60w GTX 1060 drops only 0.2v from 12.1v whether idling or folding. Is this behaviour normal, or any explanation of what is going on please.
Thanks

Do these small GPUs do 200k nowadays?
I remember running them 2 years ago, at 80k PPD (that was overclocked, and with an active fan on).

1,9V doesn't make sense. Even 10V doesn't make any sense.
I wouldn't rely on those numbers. If your GPU should run at 12V, and it drops anywhere below 11.25V to 10.75V your PC should shut down, or you'll see some magic smoke.
Many times, GPU-Z or CPU-Z don't have the correct values to read all motherboards and GPUs out there (might be a bug).

Measure your PSU's power consumption. If at the wall the PSU consumes less than it's maximum rated wattage, you should be ok.

[jrweiss]

What is the capacity of the 12V rail on the PSU? What CPU and motherboard? While the 12V rail may not be dropping to 1.9V, it may be dropping low enough to eventually cause damage to the CPU, GPU, or motherboard.

[bruce]

Power supplies are typically rated in Watts, but that's a total of the output for 5v and for 12v rails and anything else it puts out. What really matters is what can actually get to the GPU in question (or to some other devices). Watts= Volts*Amps so if the 12v rail can put out 5A, then the devices connected to it really should use less that 60 Ws.

Does your P/S have multiple 12v rails?

[iokeith]

Been a bit busy lately, but thanks for the suggestions.

I'm not really up in hardware, but can't understand how a GT 1030 can fold at 1.9v rail! The cards are fan cooled.
I've tried the card in four PCs and every time the voltage drops to approx 2v yet it still operates. This is with both PCs of PSUs 220w and 290w.

With 220w PSU XC885, the card takes 25w from PCe x16 slot and folding with a i5-8400 hex core gives approx 220k PPD at input power of 80-90w.
The PSU supplies 5v @ 10a, 12v @15A, 3.3v @ 8A

With 290w PSU Optiplex 9020, the card takes 27w from PCe x4 folds with quad core i5-4560 giving approx 180k PPD at input power of 100w,
and with an additional GTX 1650 in PCe x16 folds at 600k PPD at 170-180w. This PSU supplies 12v @ 14A, 12v @ 16A. When the GT 1030 rail is at 2v the GTX 1650 is at 11.9v

This is all at reasonable core/GPU temperatures of 60-66 C.
As have no multimeter, measurements made with Speccy, HWMonitor and TechPower GPU-Z.

Maybe I should have let it just fold, and not inquire into the details!

[ipkh]

If it is still folding, I'd consider this to be a bad sensor reading or attribution. Certainly the GPU only needs around 1V to operate and 1.9V supply clearly handles this, but it is not ideal for the power delivery.
Have you tried something like Hardware Monitor to check other voltage lines? Without checking with a multimeter it might be worth replacing that PSU as it might be going bad on that rail. Otherwise if that's the actual voltage the motherboard could be faulty as well.

[MeeLee]

Been a bit busy lately, but thanks for the suggestions.

I'm not really up in hardware, but can't understand how a GT 1030 can fold at 1.9v rail! The cards are fan cooled.
I've tried the card in four PCs and every time the voltage drops to approx 2v yet it still operates. This is with both PCs of PSUs 220w and 290w.

With 220w PSU XC885, the card takes 25w from PCe x16 slot and folding with a i5-8400 hex core gives approx 220k PPD at input power of 80-90w.
The PSU supplies 5v @ 10a, 12v @15A, 3.3v @ 8A

With 290w PSU Optiplex 9020, the card takes 27w from PCe x4 folds with quad core i5-4560 giving approx 180k PPD at input power of 100w,
and with an additional GTX 1650 in PCe x16 folds at 600k PPD at 170-180w. This PSU supplies 12v @ 14A, 12v @ 16A. When the GT 1030 rail is at 2v the GTX 1650 is at 11.9v

This is all at reasonable core/GPU temperatures of 60-66 C.
As have no multimeter, measurements made with Speccy, HWMonitor and TechPower GPU-Z.

Maybe I should have let it just fold, and not inquire into the details!

Perhaps a driver issue or bug.
The 1,9V may be 11,9V (the first digit omitted). When the readout is 2V, it could actually be 12V (again first digit omitted).
That's what I would say, makes most sense in this situation..