To me it's not as simple as comparing the efficiency under full load. I imagine the efficiency on x86 as some kind of log curve, which translates to higher power consumption even on lighter loads. Apple's ARM implementation tends to eat a lot less power on tasks that happen most of the time, hence greatly improving the battery life.

I've tried a Ryzen 7 that had a similar efficiency to an M1 according to some tests, and that thing ran hot like crazy. Its just marketing bullshit to me now..

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sgc 3 days ago | parent | next [-]

The OS matters, and I would guess you were using two different OSes? I have no doubt macOS running on an m1 is more optimized than whatever you were using on the ryzen.

I recently had to remove Windows completely from a few years old laptop with an 12th gen cpu and a Intel Iris / GeForce RTX 3060 Mobile combo because it was running very hot (90c+) and the fans were constantly running. Running Linux, I have no issues. I just double checked since I had not for several months, and temperature is 40c lower on my lap than it was propped up on a book for maximum airflow. Full disclaimer, I would have done this anyways, but the process was sped up because my wife was extremely annoyed with the noise my new-to-me computer was making, and it was cooking the components.

I have learned to start with the OS when things are tangibly off, and only eventually come back to point the finger at my hardware.

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ashirviskas 3 days ago | parent | next [-]

OS does matter, with Linux my M1 macbook gets kinda hot and it cannot do more than 1.5-2h of google meetings with cameras on. IIRC google meetings on macos were at least a bit more efficient.

Though it has definitely been getting better in the last 1.5 years using Asahi Linux and in some areas it is a better experience than most laptops running Linux (sound, cameras, etc.). The developers even wrote a full fledged physical speaker simulator just so it could be efficiently driven over its "naive" limits.

	▲	sgc 3 days ago \| parent [-]
		That is more a "who is controlling access to hardware drivers matters" problem. I wouldn't be surprised if macOS was still a tiny bit more efficient with a level playing field, but we will never know.

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petrichorko 3 days ago | parent | prev [-]

Linux can definitely help with this, I had the same experience with it on Z1 (SteamOS). But even running Windows 11 in a VM on M1 does not make the machine run hot

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ben-schaaf 3 days ago | parent | prev [-]

If we're comparing entire systems as products you're absolutely right. That's not what this discussion is about. We're trying to compare the efficiency of the ISA. What do you think would happen if AMD replaced the x86-64 decoders with ARM64 ones, and changed nothing about how the CPU idles, how high it clocks or how fast it boosts?

My guess is ARM64 is a few percent more efficient, something AMD has claimed in the past. They're now saying it would be identical, which is probably not far from the truth.

The simple fact of the matter is that the ISA is only a small part of how long your battery lasts. If you're gaming or rendering or compiling it's going to matter a lot, and Apple battery life is pretty comparable in these scenarios. If you're reading, writing, browsing or watching then your cores are going to be mostly idle, so the only thing the ISA influences won't even have a current running through it.