Hi, I’d like to share some observation.
in this post @clement mentioned, that the default tile-size in the cycles render settings might not be the optimal value depending on your GPU. That made me curious and I wanted to find out, if I might get better render times when setting different tile-sizes than the default 128x128. Thanks to @nathanletwory this is possible now.
- GPU: GTX 1060 6GB (Zotac Amp Mini @ stock speeds)
- CPU: i5 6500 (doesn’t really matter in this case)
- WIP: 2017-Mar-14
- Render Plugin: Cycles for Rhino v0.1.2
I set up a renderscene with a resolution of 2048 x 1536 Pixels, Draft Quality and 300 Samples.
then I changed the tile-size with
RhinoCycles_SetRenderOptions and let Cycles and my GPU do the work. I also kept a very rough look at the utilization of my GPU with HWMonitor.
Here are my results:
Tile-Size | Time | GPU-Utilization --------- | -------------- | ---------------- 64x64 | 00h 21m 53s 51 | ~ 13 - 57 % 128x128 | 00h 08m 14s 28 | ~ 12 - 76 % 256x256 | 00h 04m 13s 28 | ~ 18 - 98 % 512x512 | 00h 03m 30s 36 | ~ 36 - 100 % 1024x1024 | 00h 03m 15s 97 | ~ 37 - 100 % 2048x2048 | 00h 03m 09s 99 | ~ 39 - 100 % 4096x4096 | 00h 03m 10s 21 | ~ 48 - 100 %
I’m pretty happy I did this test because as you can see, by increasing the tile-size from the default 128x128 to 2048x2048 my render time decreased from 8 minutes and 14 seconds (494 seconds) to only 3 minutes and 9 seconds (189 seconds). That means an improvement of roughly 260% (please correct me if I’m wrong) - not bad, right?
I didn’t test other resolutions, so I don’t know if resolution and tile-size are related. Maybe 4096x4096 turns out to be even faster than 2048x2048 when rendering in higher resolutions.
I assume, that 2048x2048 is the sweet-spot not only for my GTX1060 but for all cards which are based on the Pascal architecture, which would be 1050, 1060, 1070, 1080 as well as 1080 Titan and Ti.
Nvidia cards based on the older Maxwell architecture might do better with a different tile-size.
I will redo the test (when I have some more time) on another system, in order to see which tile-size is optimal for a Radeon RX460 and GCN Gen4 architecture.
Beware: with the more optimal tile-size and the better utilization of the GPU, the whole system gets less responsive. Especially programs that also rely on the GPU like your browser.
I hope this information is useful for all Cycles for Rhino users.