Paul Draper wrote:Once upon a time, there were recommendations that multiple GPUs needed to be identical lest one of these fall back to the lowest speed of the other card. Alternately, one card could be used for screen-only IO, the other for GPU rendering. These days I'm not so sure this is still the case (& for these Apple MPX Raedons)
So, I have 2 x Vega IIs (not a Duo) and the xtra IO is for recording studio (many thunderbolt and USB devices). The GPU throughput on Resolve is reasonable, but am mulling the option of keeping one Vega II and possibly replacing the other with (say) a W6800x or even a Duo. & yes of course the price is mad-as but still ....
Yeah I've been wondering about that too. I still have my old 8GB Vega 64 and I was thinking of adding it to see if that unbalanced config would be any better than only having the 16GB 6900XT. But I'm not expecting it to, especially with the difference in VRAM.
I read somewhere recently on this forum that Resolve just divides all work equally between both GPUs, so if one is much more powerful you'll be bottlenecked by the slower card. So then I guess it depends on the performance differential to decide whether that's better than a single GPU. In my case I imagine it'll definitely be worse to use the weaker GPU; not certain about your situation.
I don't know if you use any other GPU-needing software? But even if Resolve doesn't improve with two mismatched GPUs, one option that might be useful would be to dedicate one or two W6800X's to Resolve, and then the VII could be used in any other software you might want to run in parallel - Fusion Studio, Blender, Cinema4D, etc. Which could be a performance benefit overall if you need/want to run multiple software in parallel.
And/or, if you use OFX plugins, you might have the option to dedicate certain GPUs to those? Neat Video for example allows you to specify which GPU(s) to use for it - so if you use that OFX you could for example dedicate the VII to Neat Video, while the 1 or 2 x 6800 is doing Resolve stuff.
Lots of possible permutations. I don't know exactly what will be the best combo, but if you can afford a W6800x or a duo W6800x, there's no way it's not going to be a massive performance boost. It's a nice problem for you to have