Just to clarify a few points in #1: CISC has gone largely (entirely?) extinct, so it doesn't play into this. Arm processors are more efficient than x86, but Risc-v is even more efficient than Arm, giving them an edge in cheap, low power computing. However, some companies have started experimenting with Risc-v for HPC applications, so it's turning out more versatile than expected. Just this week there was also news of a bunch of companies banding together to develop Risc-v chips for automobile and Telecom, so don't be surprised if we get Risc-v smartphones and tablets in the near future.