VRAM Issue with GPU-0 turned on/off

[Tommes]

I have asked myself if the following scenario is possible. Actually I couldn't test it. But maybe someone has it or knows how it works exactly.

Actual Setup:
I have 2 GPU cards with 3 GB VRAM. On the GPU-0 are 4 monitors so this card has less VRAM as GPU-1. If I want to render on both cards with Octane I have only 1,8 GB VRAM free. This counts for all additional cards I am using this way.

If I turn off the GPU-0 and only use the second one I have 2,8 GB VRAM free. So far so good and understandable.

Possible Setup:
What if I exchange the first card (GPU-0) with a Titan with 6 GB of VRAM. Than the Setup is GPU-0 = Titan with 6 GB VRAM; GPU-1 GTX 780 ti with 3 GB VRAM. Do I have 2,8 GB of VRAM available when using both cards together?

[BorisGoreta]

You are correct.

[Tommes]

You are correct.

You know it for sure? If so this would be great

[FooZe]

Hi Tommes,

I can confirm this.
The limit will be the smallest, in this case the smallest will be the 780 ti. (unless for some reason your OS + other software starts eating up more than 3.2GB of the Titan's VRAM, at which point it will become the limitation...)

Thanks
Chris.

[Tommes]

I have updated my System with one Titan as GPU card 0 for my monitors and the other 4 cards are GTX 780 ti. And I can confirm that now all (2,8 GB) of the available VRAM of the 780ti(s) is available Actually I could recommend this kind of setup if you want to use the main display card for rendering, too.