NVlink - how works it?

[Micha]

Hi,

since days I try to get more than 11GB VRAM used of two 2080ti in NVlink mode. My impression is that it doesn't work at V-Ray for Rhino. Doe's someone knows any easy test?

Here I tried a simple test - complex scene and three cards are used - 2x2080ti + 1x1080ti. The monitor is pluged to one of the 2080ti. The scene needs approx. 4GB VRAM, good to see on the 1080ti. So, my general question - why are both 2080ti using the same amount (4GB + 1,7GB system)?

The problem is, if I would disable the 1080ti for rendering, than at 11GB I would get a crash, like the 1080ti would be still used.

I don't understand the logic behind. It looks like both 2080ti need the same memory for rendering like the 1080ti, the memory isn't doubled.

I would be very glad to get it working, since I can't render my complex projects at the GPU.

-Micha

[Micha]

I removed the 1080ti to keep the setup so simple as possible. Also I installed the last recommended driver and not the newest one. I did a test and rendered a Rhino scene with NVlink and the same scene without NVlink. In both cases I have approx. 1.5GB free VRAM only and if I increase the scene complexity a little bit than V-Ray stops with a note, that there is not enough memory. Looks like there is really no increase VRAM by the NVlink here.