> And, and I can tell you that we got pretty far along with an internal Arm design, and it was very, very clear that you if you’re delivering a certain level of performance, the delta in power driven by the ISA is like 5 percent. [1]
Power matters a lot and 5% isn't almost nothing. And that's an estimate from an x86 vendor.
Agreed that it's almost certainly third though behind process and design. Intel's CPU leadership for a long time of course is not unconnected with its process leadership.
Idk for phones and larger I'd say 5% power reduction is still pretty close to nothing, especially if that's the difference between x86 and ARM. A 5w SoC becomes a 4.75w SoC - nobody is going to bat an eye at that. Similarly a 50w laptop CPU dropping to 46w is hardly transformative. It's not nothing, but it's still significantly less than a node shrink even with Moore's law being dead. And the difference between ARM and RISC-V would likely be even smaller.
You could also save way more than 5% power by just optimizing user space a tiny amount
Agreed. I think it's hard so see a new ISA getting much traction now unless it clearly offers a very significant power / performance benefit and that seems unlikely at the moment. I blogged that RISC-V might be the last mainstream ISA a while ago - I think it will crowd out other options.
Power matters a lot and 5% isn't almost nothing. And that's an estimate from an x86 vendor.
Agreed that it's almost certainly third though behind process and design. Intel's CPU leadership for a long time of course is not unconnected with its process leadership.
[1] https://www.nextplatform.com/2022/10/03/the-steady-hand-guid...