Hacker News Reader

> You might argue that 8 RISC instructions are not comparable with 8 CISC instructions, but even with say 4 CISC instructions it will still consume more energy

Alder Lake decodes six. And again, your intuition about power costs here is just simply wrong. Instruction decode is Simply Not a major part of the power budget of a modern x86 CPU. It's not.

View on HN

> And again, your intuition about power costs here is just simply wrong. Instruction decode is Simply Not a major part of the power budget of a modern x86 CPU. It's not.

I never said that instruction decode was a major part of the power budget.

And precisely, it is not because they don't decode 32 instructions in parallel. That's the purpose of an instruction length decoder prior to instruction decode.

Reply on news.ycombinator.com