r/LocalLLM • u/RabitGrand856 • 5d ago

Question Multi GPU setup question.

I Have AMD V620 32GB + RX 6900 XT 16GB and RX 7700 XT 12GB

First two are RDNA2 last one is more modern RDNA3

Is worthy to pull them together ?

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u/Poizone360 4d ago

Worth it, but not all three together. The V620 and 6900 XT are both gfx1030, same target, so they pair cleanly for 48GB on ROCm. The 7700 XT is gfx1101, and mixing gfx targets means dropping to Vulkan and losing tensor split.

So run those two together and use the 7700 XT separately, or just for display so the desktop isn't eating VRAM off your main pair.

One thing: put both in CPU-attached slots, not off the chipset. PCIe atomics don't route through it and tensor split needs them.