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by derekp7 437 days ago
You can also get an Epyc 9115 for $800, motherboard for $640, and 12 16-GiB ddr5-6400 dims for $1400, that gives you 614.4 GiB/sec, for around $2800. You may also want to add in a small GPU to do prompt processing (inference on a CPU is memory bandwidth bound, prompt processing is processing bound).
2 comments

How does CPU-based inference compare to GPU-based inference, performance-wise? And aren’t these machines likely to be used for training?
In which world do you get 614GiB/s memory bandwidth with an Epyc?

I think the best you can dream of is 480.0 GB/s, so 447 GiB/s.

I was going by the number of memory channels the CPU spec says it supports (12). But apparently I was wrong, as that gets bottlenecked by the number of CCDs on the chip. In which case you would need to go with a much higher end epyc processor, and then there are other limits. So much for napkin math