CUDA number of textures limit

[bardo]

Chaos,
as VrayRT GPU uses Cuda I suppose that has the limit of 128 bitmap textures.

Is it correct?

[savage309]

You can use more textures, generally if they fit in memory you should be okay (however if it possible to hit some limitations, but it is not really easy for me to tell you a number of max textures, since it depends...).

[bardo]

I' ve found on the web this

"...You’ve hit the 100 textures limit imposed by CUDA in Cycles. There is a 128 texture hard limit implemented by CUDA, meaning the maximum number of textures that can be bound to a kernel is 128 for CUDA versions up to and including 2.0. For 3.0 and 3.5 there is a 256 limit, but Cycles doesn’t account for the compute capabilities of 3.0 and 3.5 yet, and 28 are used internally for setup. This leaves us with a maximum of 100 textures, and 5 are allocated for HDR textures, so 95 LDR (regular textures) and 5 HDR. If you have scene with a lot of different small textures you can hit this ceiling, or if you use several HDR textures, though I suppose in most cases you’d have run out of VRAM a long ago by then..."

VrayRT GPU has some of these limitations?
And I'm not speaking about memory limit...

[savage309]

We use slightly different approach here, so we are not having this exact limit. Neither we have HDR/LDR max sizes.
There is a limit, but it is not a constant number - it depends on the size of the textures. To be honest, I haven't calculate that so far, but we can provide some examples if you want.
Also, in the current VRay RT build we don't use 3.0/3.5 cc for the texture limitations (but we do have internal build that uses them, yet it is having some issues. Once it is good enough and is released, all limitations will be dropped (at least for cc bigger or equal to 3.0)).