To check whether I understand how this all works: Wouldn't a 4 bit quant run reasonably well (for that hardware) with far less ram, something like 1.5x the 476gb, or 714gb+ ram?
Yes, but the price difference between buying a used x86-64 server with 512GB and 1024GB isn't that great, and if you're already determined to buy the hardware to run in CPU a "large" model (eg: Not Qwen 3.6 35B-A3B, gemma4 or similar size), the loss of quality and sometimes suspicious nature of the output from a 4-bit quant might be undesirable vs running a Q8 quant or full precision.
You would also want a lot of RAM for context/kv cache to make it usable so just the amount of RAM that will fit a Q4 model and run it (before any cache starts getting populated through active use) isn't enough.
You would also want a lot of RAM for context/kv cache to make it usable so just the amount of RAM that will fit a Q4 model and run it (before any cache starts getting populated through active use) isn't enough.