alt Hacker News512 MB of cache, wow.
A couple years ago I noticed that some Xeons I was using had a much cache as the ram in the systems I had growing up (millennial, so, we’re not talking about ancient commodores or whatever; real usable computers that could play Quake and everything).
But 512MB? That’s roomy. Could Puppy Linux just be held entirely in L3 cache?
CCDs can't access each other's L3 cache as their own (fabric penalty is too high to do that directly). Assuming it's anything like the 9174F that means it's really 8 groups of 2 cores that each have 64 MB of L3 cache. Still enormous, and you can still access data over the infinity fabric with penalties, but not quite a block of 512 MB of cache on a single 16 core block that it might sound like at first.
Zen 4 also had 96 MB per CCD variants like the 9184X, so 768 MB per, and they are dual socket so you can end up with a 1.5 GB of total L3 cache single machine! The downside being now beyond CCD<->CCD latencies you have socket<->socket latencies.