You could get a pair of used epyc 7601 and a motherboard for like $1200. Unlike a hundred little pentium cores, these 64 cores can run real workloads ~4x as fast as a modern desktop in the same price range.
Alternatively an old 4 node server could get you there even cheaper if you don’t care that they are separate computers in one chassis. I got a used C6100 with 24 cores across 8 CPU sockets for $600 6 years ago. You could probably get >100 cores for the same price today.
For the most part, because you'd be IO-bound, and you'd be limited by single-threaded speed.
A better architecture is to have the same, but as a co-processor for highly multithreaded tasks. That's basically a GPU. You get a few thousand cores on an NVidia 3060, in an architecture designed for this.
To the other comments in the thread:
- I'm mostly giving big-O / ballpark numbers.
- In terms of power, Pentium IV was 180 nm - 65 nm. A 7 nm process can be much more power-efficient.
Or one that doesn’t cost big dollars since the arm server chips seem to be going in this direction.
I mean, 256 x86 cores seems perfectly reasonable, right?