Tips in Speeding Up Cycles Render

Just testing out Cycles, just recalled some ways to speed up render so posting.
Maybe you guys know it already…
(save files first… not sure how it works in your computers)

This is mainly for the rendering via GPU.
Making Tile size bigger maybe 1/3 size of output size of render.
so if you are making 3000px x 3000px, setting tile to 1000 x 1000
(well you can try what works) Maybe going to far might lead to crashes, not tried that far yet…

For CPU not sure for RhinoCycles but there should be hyperthreading option probably somewhere for those CPU that can support it.

Anyway to speed up render:

  1. In Rhino Options -> Advanced -> type in “cycles” to filter cylces menu.
  2. In RhinoCycles.tilex & RhinoCycles.tiley change from 128 to something bigger.

I tested 128, 500, and 1000 and below are for time taken for 3 sampling.
(128) 18.56sec -> (500) 13.68sec -> not attached(1000) 8.95sec
Time is more than half, but I guess depends on the scene.
I also reduced bounces in the lighting and some others to speed up in general.
That’s just quality vs. speed, and your preference.


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Hello TT,
this with the “Tile Size” is good point.
In BlenderCycles was tested:
on GPU bigger then 512 x 512 was the fastest
on CPU 16 x 16 was the fastest

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A warning regarding the advanced settings. I’ll be soon making a pass to rename them to PascalCase style to be more like the rest of settings.

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There should also be ways to reduce the fireflies,
but still looking and recalling the settings…

You want to check the direct clamping settings and filtering size. Note that we don’t support denoising yet.

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Thank you for the tip!
Rendering transparent things looks pretty good already compared with RhinoRender.

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Instead of going to the options menu you can also set the tile-size and other cycles options like the sample count via the command panel by using this command:
RhinoCycles_SetRenderOptions

Use this to specifically target the tile-size:
RhinoCycles_SetRenderOptions tile_x 512 tile_y 512 _enter

I came to the same conclusion: bigger tile size than the default 128 results in faster renderings.

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Cool thanks for the tip!