Unlike in the eighties and nineties, CPU front-end (instruction decode) is hardly an issue in modern times. Oversimplified, front-end translates instructions in

Unlike in the eighties and nineties, CPU front-end (instruction decode) is hardly an issue in modern times. Oversimplified, front-end translates instructions into something the CPU really understands. This part of the CPU used to be significant amount of die area, but not so anymore. CPU back-end is what matters, and the answer there is that it doesn't make practically any difference. For general purpose computing, RISC vs CISC is practically a dead topic now. Of course you would not want a complicated CISC front-end in microcontroller. But that's another topic.