[blasdel]

Don't forget that Rome also has a wildly nonuniform interconnect between the core complexes, and the system integrator gets much less control over it than Intel's UPI links. When you really need to end up with a very large single system image at the application layer, the bigger architecture works out to be much cheaper than 256gb DIMMs or HPC networking.

8-socket CLX nets you 1.75x the cores, and 3x as many memory channels vs. a 2-socket Rome system. It also scales to a single system image with 32 sockets if you use a fabric to connect smaller nodes:

* 4-socket nodes: https://www.hpe.com/us/en/servers/superdome.html

* 2-socket nodes: https://atos.net/en/solutions/enterprise-servers/bullsequana...

That's 48tb of DRAM with all 128gb DIMMs, or 12tb+128tb when using 512gb Optane PDIMMs.