Sunway SW26010

260 cores on one die, arranged as four groups of one management element plus an eight-by-eight mesh of 64 compute elements, each with a small scratchpad instead of a cache hierarchy. This is not a CPU with accelerators attached; it is the accelerator and the host on the same piece of silicon, seven years before that became fashionable. Every part of it is domestic: the ISA, the design, the fabrication at SMIC, the fabric and the operating system, and Sunway TaihuLight is the first system in this dataset to score 1.0 on the domestic-substitution index. It was also brutally hard to program, which is the cost of owning your whole stack.