SSS difference between GPU and CPU

[am_wilkins]

Hello,

I've noticed a pretty massive difference between SSS on the GPU vs the CPU.
Same scene, same shader, same lights, etc.

Simple setup, just a mask driving the subsurface and a color chosen for the scattering color.

Type: Diffusion

Arnold Standard Surface (Not Material X)

Arnold CPU:

Arnold GPU:

The colour is just becoming white?

amwilkins

--

Houdini Core Version 20.0.590
Arnold Core: 7.2.5.2

HotA: 6.2.5.2

CPU: AMD Ryzen TR 3990x

RAM: 128GB
GPU: NVIDIA RTX A4000
OS: Windows

[lee_griggs · Accepted solution]

From the GPU docs:

Try randomwalk 1/2 instead.

[am_wilkins]

Hi,

Thanks this seems to do the trick. 

I hadn't checked that "Supported Features and Known Limitations" page for quite a few months, thought most features such as these would have parity. Good to know!

I was picking "Diffusion" for optimization reasons. Will use Randomwalk for now.

All the best,

amwilkins