I was browsing the system76 page for servers https://www.system76.com/servers/model/jacp8 and i realized that when u check the option for a second processor you must choose memory for that processor. In dual processor systems, does the memory get shared? In my old powermac g4 with 2 processors i remember they are shared.
Multiple socket systems that do not share memory (along with cache coherence) are relatively exotic (Calxeda's EnergyCard is an example) and System76 is more of a whitebox vendor than a specialized system designer. The use of 2xxx versions indicates System76 are paying Intel for support of cache coherence and memory sharing, so it is very unlikely that they would be using them in some kind of mini-cluster-on-a-motherboard design.