CPU vs GPU shading

[lacilaci]

why am I seeing shading errors on gpu but not on cpu with the same settings?

Now, this scene is a bit of a stretch case I tried to emulate problem I usually see on some cad models but it is also visible in the luxcore benchmark scene from sharlybg, faintly though.

There are ways to solve this I know but in some cases I'm afraid my only option would be to use cpu rendering.

[kintuX]

IDK, might be a bug...
At first, it looks like min. epsilon value behaves differently on GPU vs. CPU. For GPU it must be set 100x higher, then both give same result.
Same behavior is observed in standalone.
Didn't look further.

[FarbigeWelt]

I made the observation, but had to increase min. epsilon by factor 500. It depends much on how the edges are connected in the shape. This glitches are often seen with GPU rendering after bolean operation difference.