As of writing, the most dense server CPU is the AMD EPYC 9965, which has 192 cores. It is possible to build a 2x CPU 1U server, so that is 384 cores per 1U. I am unsure what is the limiting factor: heat or space on the die (probably lots is just L1/2/3 cache). When you look at the interior of a vanilla 1U server, I don't think there is any remaining space to add more sockets (CPUs). Final note: SuperMicro also offers an Ampere ARM chip with 192 cores.
As of writing, the most dense server CPU is the AMD EPYC 9965, which has 192 cores. It is possible to build a 2x CPU 1U server, so that is 384 cores per 1U. I am unsure what is the limiting factor: heat or space on the die (probably lots is just L1/2/3 cache). When you look at the interior of a vanilla 1U server, I don't think there is any remaining space to add more sockets (CPUs). Final note: SuperMicro also offers an Ampere ARM chip with 192 cores.