Don't know about AMD collaboration, but their home-grown supercomputers use some home-grown ISA, reportedly roughly based on an extended variant of MIPS. As an

Don't know about AMD collaboration, but their home-grown supercomputers use some home-grown ISA, reportedly roughly based on an extended variant of MIPS. As an aside, it was long before Trumps trade war with China that USA refused to sell chips for Chinese supercomputers, prompting them to seriously start developing their own. Will be interesting whether we'll see Chinese POWER designs, or whether they continue with MIPS and RISC-V.