PRC's Tua Leng Kong supercomputer uses SELF-MADE CPU developed on Open-Sourced CPU core design. Integrated their own CPU chip with multi-core and 10Gbps fiber LAN to inter-connect thousands of such CPU ships across the many black steel cabinets. Cache inside also.
Intel Xeon had been taken off from 2 generations ago.
For high performance it is important to have tons of RAM DIRECTLY AVAILABLE to each CPU chip instead of via LAN no matter how fast yr LAN. As much as possible each CPU chip directly map tons of RAM without LAN because LAN I/O speed is really slow compared to memory mapped speed. Speed starts to Crawl when the memory needed for CPU read/write is not directly mapped, and have to page swap via supercomputer LAN.