Basically for Telum II, (I don't know what changed here from Telum III, the core under discussion with the ARM decoders) each CPU core has a giant 36MB L2 cache. Then, rather than a discrete L3 cache, the cores keep track of L2 residency needed for that core's working set, and allocate the rest of their L2 to a shared pool that is the L3 cache. Then the same thing with L4 being the same pools in all of the other chips on the same drawer (which you can kind of think of as close to a single server).

https://chipsandcheese.com/p/telum-ii-at-hot-chips-2024-main...