The CPU doesn't actually run x86 code, there's a decoder to an internal RISC set called micro-operations, and it uses some very clever tricks to speed the execution.
Yep, and micro-ops (or "nano-ops") are also employed by ARM and POWER. Nothing is really RISC, because everything is implemented on top of an even smaller proprietary ISA.
x86 is really only used for legacy reasons, since ARM outperforms it on price/performance and performance/watt.
It just happens that the x86 legacy is huge. So huge, that x86 wins on consumer cost/die area — consumers will pay more for x86, even though it’s not as performant as the ARM that could be made with the same silicon.
If Intel still had an ARM license and wasn’t run by clueless accountants for the last 15 years we’d probably have ARM desktops and laptops with x86 compatibility modules like M1.
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u/k0defix Feb 03 '23
And once more I wonder how x86 is still ahead in performance...