Iray GPU usage

SethM

I'm curious about CPU vs. GPU usage with Iray. I have an NVidia GTX 760 (192-bit) that NVidia claims has 1152 CUDA cores. In my render settings I have tried checking just the GeForce as well as checking both the GeForce and the CPU. In either case, Process Explorer claims my GPU cores are basically idle and my CPU is (clearly) pegged. GeForce Experience says I'm on the latest drivers (version 358.50) and I am using Windows 10.

I don't "feel" any real speedup with the GPU checked, but that's pretty unreliable (at least with me). I don't know if I trust GPU the metrics from Process Explorer (this is the first time I've ever bothered with them).

Should I just trust that Iray is using my GPU fully? Even if I shouldn't, do I have a better option? Am I overthinking this and should just hit render and go watch TV?

Thanks for any insight.

nicstt

Have you selected GPU in the render options; the advanced tab I think its under, I can't check atm. Uncheck CPU, perhaps too. That card should be somewhat quicker than CPU. If you have more than one GPU, then some with Windows 10 are reporting issues.

fastbike1

Windows 10 and Geforce Experience had some early issues that are supposedly fixed. Nonetheless, i personally found Geforce experience to be more trouble than it was worth (also found same w/ Windows 10 and went back to Win 7).

I would recommend uninstalling Geforce Experience and trying again. When I had Win 10 installed, without Geforce Experience, I was able to render with my GTX780.

Lindsey

Could the bottleneck be GPU memory?   On Windows,  I use GPU Meter (a Windows Gadget) to monitor memory usage on my Nvidia GPU and it's showing rendering one Genesis 2 Female with it's default texture can load over 2 GB into my GPU.  If you're on Windows and don't use Windows Gadgets, GPU-Z is a frequently recommended stand-alone Windows application that can monitor GPU memory usage.

SethM

Thanks for the answers. I checked my settings and I did have GPU rendering enabled (and tried with and without CPU enabled as well). I then downloaded GPU-Z and it gave a very different picture, suggesting that the GPU rendering was working as expected. I'm gong to put this down to a limitation in whatever version of ProcExp I'm using magnified by my impatience and my mistrust of my setup.

 

Thanks again!

Tobor

D|S itself will tell you if it used your GPU in a render. Do a test scene, and immediately after rendering is finished, choose Helk->Troubleshooting->View Log File. Iray will tell you what it used for the render with some level of detail, including the number of devices, iterations handled per device, and total render contribution of each device, in seconds. If it tried to use your GPU, but couldn't, it'll indicate that too, though the reason may be a bit cryptic.