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Comment by lossolo | Hacker News Reader

Buy 4–8 used 3090s (providing 96–192 GB of VRAM), depending on the model and weight quantization you want to run. Used 3090 costs around $800. Add more RAM to offload layers if needed. This setup currently offers the best value for performance.

https://www.reddit.com/r/LocalLLaMA/comments/1iqpzpk/8x_rtx_...

You can look for more rig examples on that subreddit.

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I do wonder what the ongoing cost there would be. The ~$9k hardware cost is an easy thing to quantify, but going with a bank of very hot, power hungry GPU's is going to rack up a hefty monthly bill in many parts of the world.

I imagine theres also going to be some problems hooking something like that up to a normal wall socket in North America? (I like the reddit poster am in Europe so on 220v)

It's not too bad - I run 6x RTX 3090s on a 2nd-gen Threadripper with PCIe bifurcation cards. The energy usage is only really bad if you're training models constantly, but inference is light enough.

I use 208V power but 120V can indeed be a challenge. The USA has split phase wiring; every house has 220-240V if they need it. Bit of a misunderstanding of how our power works - we have 220-240V on tap, but typical outlets are 110-120V.

Yeah at this point the goal is to see how to maximize for inference. For training it is impossible from the get go to compete with the frontier labs anyway. Im trying to calculate (even amortized over 2 years) the daily cost of running the equivalent rig that can get close to a single claude agent performance. (without needing a 6-digit gpu).

Really the only reason to have a local setup is for 24/7 on-demand high-volume inference that can't tolerate enormous cold starts.

Yeah this was what I was doubting too. Like the hardware is one off but how much do you have to modernize your house (lines, cooling, eletrical-fire-safety etc)?

Also I wonder if like the old days you could "try" these out somewhere first. Imaging plonking down 5-10k and nothing works (which is fine if you can get a refund ha).

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