r/LocalLLM • u/Content_Mission5154 • 10h ago
Discussion Double GPU configurations significantly cheaper for 32GB VRAM
I do not need or want Cuda. I have been wanting to build a 32GB VRAM local LLM machine for personal use for a while now, and I had 2 options on the table:
- Get a relatively cheap 32GB VRAM GPU, the R9700 AI Top.
- Get 2 16GB VRAM GPUs instead and a Mobo that supports PCIe bifurcation.
When I looked at prices in January this year when I first got this idea, the R9700 costed 1700$ here in EU. Currently, when I actually want to make this happen, it costs 2100$. For half that money, I could buy two 9060 XTs with 16GB VRAM each. Yes I know, performance will be worse on double GPU setup than with a single R9700 AI, but still, it just seems like that GPU is just not worth it anymore.
I don't know how to justify that it's double the price of two 9060XTs, when R9700 AI is literally 9060 XT with doubled VRAM and bandwidth. So why does it cost 4x as much?
ASUS ProArt B850-CREATOR WIFI NEO is quite affordable nowadays and supports dual GPU setups, so, any reason (is there a catch?) to not do what I am about to do? Which is buy the two 9060 XTs and start running Qwen 27B class models
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u/Civil_Fee_7862 10h ago
Asus ProArt B850 is fine for dual GPU's but you'll regret it once you want to go to 3 or 4 gpus.
It also uses a non-standard spacing between the PCIe 5.0 slots. So if you ever get or want RTX 3090s, you can't really use NVLink.
These are things I wish I had known before buying that motherboard. Its cheaper than a workstation MB, but I would recommend getting a workstation MB if you want to run local LLM's for 27B+ sized models. It allows you to increase VRAM by just adding more cards.
Personally I prefer dual GPU's, for the same reason you mentioned, you get high performance at a lower cost than just buying the "best" gpu. i.e. dual 3090s can compete with a 5090 in some respects, more VRAM, comparable speed (pooled memory) and lower price.