I have a potentially bad idea, but I wanted to get all of your expertise to make sure I'm not going down a fruitless rabbit hole.

TLDR: I have a one PC with a 4070 12gb and one PC with a 3060 12gb. I run AI on both separately. I purchased a 5060 Ti 16gb.

My crazy idea is to get a new motherboard that will hold 2 graphics cards and use ComfyUI-MultiGPU to set up one of the PCs to run two GPUs (Most likely the 4070 12gb and 3060 12gb) and allow it to offload some things from the VRAM of the first GPU to the second GPU.

From what I've read in the ComfyUI-MultiGPU info it doesn't allow for things like processing on both GPUs at the same time, only swapping things from the memory of one GPU to the other.

It seems (and this is where I could be mistaken) that while this wouldn't give me the equivalent of 24GB of VRAM it might allow for things like GGUF swaps onto and off of the GPU and allow the usage of models over 12GB in the right circumstances.

The multi-GPU motherboards I am looking at are around $170-$200 or so and I figured I'd swap everything else from my old motherboard.

Has anyone had experience with a set up like this and was it worth it? did it help in enough cases that it was a benefit?

As it is I run two pcs and this allows me to do separate things simultaneously.

However, with many things like GGUF and block swapping allowing things to be run on cards with 12GB this might be a bit of a wild goose chance.

What would the biggest benefit of a set up like this be if any?