GPU 26% TDP on IDLE

[Delphis]

Hello,
I got 3x GTX 780Ti, 1 on motherboard-primary for display and 2 on PCIe Risers dedicated just for OctaneC4D rendering.

I noticed that one of GPUs on riser (not primary display GPU) is getting hotter (50C) and 26% TDP when C4D is just started and idle. Other GPUs are at 5% TDP when on idle and temps are around 30C.
When I exit C4D, all 3 GPUs are at low TDP, primary a little more loaded but those 2 on risers are under 5%.

Tried to change PCIe ports, but always on of GPU on riser is getting 26% TDP for unknown reason.

How come that C4D loads that GPU just on IDLE and is there any settings to avoid that unnecessary load/heatting of GPU?

Thank you.

[aoktar]

If you have any cuda context, gpu will not be idle. Press reset button or don't keep open LV. Also octane previews can create cuda data.

[Delphis]

No Octane or LV is used, C4D is just started and doing nothing. And still it uses CUDA from that one GPU.

[Delphis]

Here is screengrab of GPU uses when start to model or play something in C4D.
First (primary display) GPU is at 50% load and power use is 17%
Notice that second card is still fixed at 26-27% and GPU load is 0$ !?

[glimpse]

Are those the same model cards? Or do they differ in any case?

What I see from screen grabs is that your 2nd GPUs memory is running at higher clock speed, got more voltage..so it's whether it is taxed out with something from the system, or card is staying "alert" not running but ready..

you're not alone who notice these things..but it seems..some GPUs stay like this..even if You turn out some programs.

[aoktar]

if it's a octane issue, should see all of them at a high TDP. Plugin shouldn't use gpu when it's not called on startup.

[Delphis]

GPUs are (in order of appearance):
EVGA 780 Ti ACX Cooler
Gigabyte GV-N78TOC-3GD
Gigabyte GV-N78TGHZ-3GD

They are all different, so clocks are different for a reason, and they are all raise clock as 2nd GPU when they are not idle (Octane rendering or other cuda usage).
Its obvious that 2nd card is loaded for some reason even application is not doing anything, but I have no logical clue why C4D is using CUDAs in so called idle state.
Different case is with Photoshop, when started it raises TDP to 26% for all GPUs and stay that way even PS is idle and no action is given from user side.
After effects does not raise TDP for 2nd and 3rd GPU.
When I switch PCIe ports its the case that one of those two GPUs is always have 26% TDP when C4D is started.

It's not Octane specific problem but I'm wondering why is that so, anyway if I'm just modeling 2nd GPU is loaded to fixed 26% TDP and heating for no apparent reason, since primary display GPU take all the GPU load from user actions, 2nd just "sits" there with fixed TDP.

Again, I just used other PCIe ports for 2nd and 3rd GPU and here are screen grabs again:

[TonyBoy]

Sounds like a problem for video card engineers and Maxon.

[Delphis]

I discovered that some demo plugs I had installed did that unnecessary power drain in idle (Thea render and TurbulenceFD).
De-installed them and now everything is OK in idle, but problem persists when you work with anithing that uses cuda, example select some mesh in scene with octane setup (materials, camera etc.), middle mouse for quad view and power drain jumps to 27% for all GPUs and stays there all the time. Anyway its related with cuda usage, when I remove Octane plugin and do the same action, no power drain activated.

Guess that's nvidia driver problem and there is nothing to do about it