Not as I read it: > Going for custom proprietary instruction-sets is thus not a good idea (In reference to why you'd use RISCV for co-processors in general)

Not as I read it: > Going for custom proprietary instruction-sets is thus not a good idea (In reference to why you'd use RISCV for co-processors in general) I'm arguing the custom ISA is essential to building the co-processor (or at least makes it easier). The fact your application is super specialised means the existing RISC-V software ecosystem doesn't really help you. Nvidia's use of RISC-V is incidental, not a key part of their GPU architecture.