GPU utilization with RTX20

Had an RX580 for quite a long time and I was very happy with its viewport performance and display quality in rhino viewport. A few months ago I was basically forced to switch to an RTX2070Super because support for AMD in rhino-cycles is simply broke or was never seriously wired up. Was fed up complaining about it.
I noticed that not even the RTX card works particularly well in rhino-cycles. Utilization while rendering is around 75% at best in RH6, sometimes lower, depending on the scene. With RH7 it is over 80% utilization now, still far from ideal. Something I can do to get better utilization? On RH6 I tried a lot and I don’t think more that ~75% isn’t possible. RH7 is hopefully different?

Btw,
don’t use the integrated Windows tools to monitor GPU utilization, it’s not accurate. Please use GPU-Z or HWiNFO.

I use MSI Afterburner.

Utilization of GPU will depend on scene. If it isn’t too complicated you won’t see high GPU utilization.

If you set it to compute or cuda to monitor it well be very close to if not the same as the tools you linked

Yes, MSI Afterburner is good for that as well.
OK, that may be a reason. My scenes are overall not that complex. Would more geometry or higher resolution make the GPU sweat more? Never mind, I’ll try when I need to render again. If my scenes are just not complex enough then I can’t complain of course. Not completely convinced that this is really the case here, like mentioned, I’ll look closer next time I render :wink:

Complexity for a raytraced means at least more rays to trace. Lots of geometry helps a bit, but lots of reflective surfaces, transmissive surfaces, emissive surfaces, many lights, high bounce counts. Those are the things that make a scene complex for a raytraced.

Here a quick comparison between MSI afterburner and Windows Task Manager with one of the graphs set to CUDA. They are pretty similar…

Yes, “CUDA” in Windows Taskmanager is the same as “GPU-Load” in GPU-Z, “GPU Core Load” in HWiNFO64 and “GPU3 usage” in Afterburner. Looks like Microsoft has done some improving since they first added it to the Taskmanager.

Have you ever managed to utilize your RTX closer to 90% or even more with rhino cycles? Has anyone?

You can get to 100% by setting the Throttle MS setting in Tools > Options > Cycles to 0. This may make your system unresponsive though, especially if the GPU is the only one and/or used as display device, so play with care.

1 Like

OK, that would be undesired of course. Good to know it does not seem to be a limitation of the rhino-cycles implementation.
I used to have my old GTX1060 in the system as display card and used the 2070Super for rendering only. But currently I don’t need to render as much any more and they both had little breathing room, so I threw out the old 1060 for now. Had thought about a second 2070Super but since the recent RTX3000 announcement that does not make a lot of sense.

The bane of every computer owner

Will the RTX3000 series be supported right from the start with the latest RH7 or will that take time? I know blender needs to support it first, they seem to be pretty quick with that, usually. Though the nvidia marketing makes it look like it’s much more cuda cores compared to prev gen turing, it is actually more like pretty beefed up cuda cores. so the architectural changes might require some extra time to adapt the software? Apart from that, Optix support would be what I’m looking forward to the most.

I just need to ensure I compile the CUDA kernels for the version.

1 Like