Wrong GPU usage?

[oblivion]

Hi there,

In my rig I have a rtx 3090 and a 2080 super. When firing up the live viewer, and looking at the stats, it uses the vram of the 2080 super, which is ofc not what I want. When I disable the 2080 super, it immediately uses the vram of the 3090. Is there a way to use both cards, but using the vram of the 3090?`

Best Oblivion

[aoktar]

It's using both memory but as lowest vram. Because it's keeping same data on both for rendering. It's not like serial math, parallel

[frankmci]

To put it a little differently, Octane memory is constrained by the card with the lowest amount of available VRAM, because it needs to be able to do the exact same operations on both cards in parallel. With the smaller card active, it is constrained by the lower available memory, so that's what it displays as the max available. When you turn the smaller card off and just use the larger card, it's the larger card's memory that is the constraint.

[oblivion]

I see, that makes sense. Thank you for the explanation