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Ask HN: Why hasn't x86 caught up with Apple M series?

447 points stephenheron | 1 comments | 25 Aug 25 21:50 UTC | HN request time: 0s | source

Hi,

My daily workhorse is a M1 Pro that I purchased on release date, It has been one of the best tech purchases I have made, even now it really deals with anything I throw at it. My daily work load is regularly having a Android emulator, iOS simulator and a number of Dockers containers running simultaneously and I never hear the fans, battery life has taken a bit of a hit but it is still very respectable.

I wanted a new personal laptop, and I was debating between a MacBook Air or going for a Framework 13 with Linux. I wanted to lean into learning something new so went with the Framework and I must admit I am regretting it a bit.

The M1 was released back in 2020 and I bought the Ryzen AI 340 which is one of the newest 2025 chips from AMD, so AMD has 5 years of extra development and I had expected them to get close to the M1 in terms of battery efficiency and thermals.

The Ryzen is using a TSMC N4P process compared to the older N5 process, I managed to find a TSMC press release showing the performance/efficiency gains from the newer process: “When compared to N5, N4P offers users a reported +11% performance boost or a 22% reduction in power consumption. Beyond that, N4P can offer users a 6% increase in transistor density over N5”

I am sorely disappointed, using the Framework feels like using an older Intel based Mac. If I open too many tabs in Chrome I can feel the bottom of the laptop getting hot, open a YouTube video and the fans will often spin up.

Why haven’t AMD/Intel been able to catch up? Is x86 just not able to keep up with the ARM architecture? When can we expect a x86 laptop chip to match the M1 in efficiency/thermals?!

To be fair I haven’t tried Windows on the Framework yet it might be my Linux setup being inefficient.

Cheers, Stephen

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gettingoverit ◴[26 Aug 25 11:22 UTC] No.45025038[source]▶
> might be my Linux setup being inefficient

Given that videos spin up those coolers, there is actually a problem with your GPU setup on Linux, and I expect there'd be an improvement if you managed to fix it.

Another thing is that Chrome on Linux tends to consume exorbitant amount of power with all the background processes, inefficient rendering and disk IO, so updating it to one of the latest versions and enabling "memory saving" might help a lot.

Switching to another scheduler, reducing interrupt rate etc. probably help too.

Linux on my current laptop reduced battery time x12 compared to Windows, and a bunch of optimizations like that managed to improve the situation to something like x6, i.e. it's still very bad.

> Is x86 just not able to keep up with the ARM architecture?

Yes and no. x86 is inherently inefficient, and most of the progress over last two decades was about offloading computations to some more advanced and efficient coprocessors. That's how we got GPUs, DMA on M.2 and Ethernet controllers.

That said, it's unlikely that x86 specifically is what wastes your battery. I would rather blame Linux, suspect its CPU frequency/power drivers are misbehaving on some CPUs, and unfortunately have no idea how to fix it.

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akho ◴[26 Aug 25 12:11 UTC] No.45025451[source]▶
x12 and x6 do not seem plausible. Something is very wrong.
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loudmax ◴[26 Aug 25 13:08 UTC] No.45026028[source]▶
These figures are very plausible. Most Linux distros are terribly inefficient by default.

Linux can actually meet or even exceed Window's power efficiently, at least at some tasks, but it takes a lot of work to get there. I'd start with powertop and TLP.

As usual, the Arch wiki is a good place to find more information: https://wiki.archlinux.org/title/Power_management

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akho ◴[26 Aug 25 13:43 UTC] No.45026450[source]▶
Those numbers would imply <1h runtime, or a >50W consumption at idle (for typical battery capacities). That's insane.

I've used Linux laptops since ~2007, and am well aware of the issues. 12x is well beyond normal.

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E39M5S62 ◴[26 Aug 25 15:46 UTC] No.45028156[source]▶
At least on Thinkpads over the years, I've never seen anything remotely close to that either. I've had my Thinkpad x260 power draw down to 2.5 watts at idle, and around 4 or 5 watts with a browser and a few terminals open. That was back in 2018! With the hot-swappable battery on the back, I could go for 24 hours of active use without concern.
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1. akho ◴[26 Aug 25 17:06 UTC] No.45029366[source]▶
I get below 5W at idle (ff and emacs open, screen at indoor brightness, wifi on) on my gen11 framework. Going from 8 to 5 required some tinkering.

I don't think I ever saw 50W at all, even under load; they probably run an Ultra U1xxH, permanently turbo-boosted.

For some reason. Given the level of tinkering (with schedulers and interrupt frequencies), it's likely self-imposed at this point, but you never know.