I plan to infer 33B models at full precision, 70B is second priority but a nice touch. Would I be better off getting an AMD EPYC server cpu like this or a RTX 4090? With the EPYC, i am able to get 384GB DDR4 RAM for ~400USD on ebay, the 4090 only has 24GB. Moreover, both the 4090 and EPYC setup + ram cost about the same. which would be a better buy?
Unquantized, 34B models require at least 65GB plus extra depending on context. I cannot see how your comparison of alternatives can work.
You would need 3 x 4090 to run the model.