There are two entities allowed to make x86_64 chips (and that only because AMD won the 64 bit ISA competition, otherwise there'd be only Intel). They get to choose.
The rest will use arm because that's all they have access to.
Oh, and x86_64 will be as power efficient as arm when one of the two entities will stop competing on having larger numbers and actually worry about power management. Maybe provide a ?linux? optimized for power consumption.
Unless you badly need SSE4 or AVX (and can't get around the somewhat questionable patent situation) anyone can make an x86_64 chip. And those patents are running out soon.
Sounds like your M2 is hitting the TDP max and the Ryzen box isn't.
Keep in mind there are Nvidia-designed chips (eg. Switch 2) that use all of ten watts when playing Cyberpunk 2077. Manufactured on Samsung's 8nm node, no less. It's a bit of a pre-beaten horse, but people aren't joking when they say Apple's GPU and CPU designs leave a lot of efficiency on the table.
If you're measuring the draw at the wall, AFAIK desktop Ryzen keeps the chipset running at full power all the time and so even if the CPU is idle, it's hard to drop below, say, ~70W at the wall (including peripherals, fans, PSU efficiency etc).
Apparently desktop Intel is able to drop all the way down to under 10W on idle.
The last 20% of the performance takes like >75% of the power with Zen 4 systems XD.
A Ryzen 9 7945HX mini pc I have achieves like ~80% of the all-core performance at 55W of my Ryzen 9 7950X desktop, which uses 225W for the CPU (admittedly, the defaults).
I think limiting the desktop CPU to 105W only dropped the performance by 10%. I haven't done that test in awhile because I was having some stability problems I couldn't be bothered to diagnose.
I was doing yocto builds at the time i limited the power. A full build from scratch was measured in hours. I didn't notice a significant slowdown after I put the power limit in.
> Oh, and x86_64 will be as power efficient as arm when one of the two entities will stop competing on having larger numbers and actually worry about power management.
Both Intel and AMD provide runtime power control so this is tunable. The last ~10% of performance requires far more than 10% of the power.
I remember hearing on one of the podcasts I listened to about the difference between the Apple power cores and efficiency cores.
The power ones have more execution units I think, and are allowed to run faster.
When running the same task, the efficiency ones are just ridiculously more efficient. I wish I had some link to cite.
The extra speed the power units are allowed is enough to tip them way over the line of exponential power usage. I’ve always known each bump in megahertz comes with a big power cost but it was eye-opening.
There are two entities allowed to make x86_64 chips (and that only because AMD won the 64 bit ISA competition, otherwise there'd be only Intel). They get to choose.
The rest will use arm because that's all they have access to.
Oh, and x86_64 will be as power efficient as arm when one of the two entities will stop competing on having larger numbers and actually worry about power management. Maybe provide a ?linux? optimized for power consumption.