Why E cores make Apple silicon fast

(eclecticlight.co)

65 points | by ingve 2 hours ago ago

45 comments

  • drob518 3 minutes ago

    Does anyone have any insight into the MacOS scheduler and the algorithm it uses to place threads on E vs. P cores? Is it as simple as noting whether a thread was last suspended blocking on I/O or for a time slice timeout and mapping I/O blockers to E cores and time slice blockers to P cores? Or does the programmer indicate a static mapping at thread creation? I write code on a Mac all the time, but I use Clojure and all the low level OS decisions are opaque to me.

  • roomey 43 minutes ago

    Genuine question, when people talk about apple silicon being fast, is the comparison to windows intel laptops, or Mac intel architecture?

    Because, when running a Linux intel laptop, even with crowd strike and a LOT of corporate ware, there is no slowness.

    When blogs talk about "fast" like this I always assumed it was for heavy lifting, such as video editing or AI stuff, not just day to day regular stuff.

    I'm confused, is there a speed difference in day to day corporate work between new Macs and new Linux laptops?

    Thank you

    • nerdsniper 22 minutes ago

      I use pretty much all platforms and architectures as my "daily drivers" - x64, Apple Silicon, and ARM Cortex, with various mixtures of Linux/Mac/Windows.

      When Apple released Apple Silicon, it was a huge breath of fresh air - suddenly the web became snappy again! And the battery lasted forever! Software has bloated to slow down MacBooks again, RAM can often be a major limiting factor in performance, and battery life is more variable now.

      Intel is finally catching up to Apple for the first time since 2020. Panther Lake is very competitive on everything except single-core performance (including battery life). Panther Lake CPU's arguably have better features as well - Intel QSV is great if you compile ffmpeg to use it for encoding, and it's easier to use local AI models with OpenVINO than it is to figure out how to use the Apple NPU's. Intel has better tools for sampling/tracing performance analysis, and you can actually see check you're loading the iGPU (which is quite performant) and how much memory you're using. The iGPU's can also be configured to use varying amounts of system RAM - I'm not sure how that compares to Apple's unified memory for effective VRAM, and Apple has higher memory bandwidth/lower latency.

      I'm not saying that Intel has matched Apple, but it's competitive in the latest generation.

    • smw 38 minutes ago

      Apple silicon is very fast per size/watt. The mind blowing thing is the macbook air that has weighs very little, doesn't have a fan, and feels competitive with top of the line desktop pcs.

      • drob518 a minute ago

        My M1 MacBook Air is honestly the best laptop I’ve ever owned. Still snappy and responsive years after release. Fantastic machine. I’m starting to crave an M5 Air…

      • eru 24 minutes ago

        Of course, it's only competitive for short bursts of serious CPU work. The thermal limits do kick in pretty quickly.

        (I love my MacBook Air, but it does have its limits.)

        • nerdsniper 20 minutes ago

          I looked into this for the M1 MBA and it had the exact same performance at full load as the MBP...for 7 minutes. Then the thermal throttling hits and it slows down. I'm not sure what the time limit is for newer models. Regardless, the MBA's aren't offered with Pro/Ultra chips, which I desire (and would thermally throttle much sooner than 7 minutes).

          My recommendation to friends asking about MBP / MBA is entirely based on whether they do anything that will load the CPU for more than 7 minutes. For me, I need the fans. I even use Macs Fan Control[0], a 3rd party utility, to control the fans for some of my workflows - pegging the fans to 100% to pre-cool the CPU between loads can help a lot.

          0: https://crystalidea.com/macs-fan-control

          • eru 9 minutes ago

            I guess the details depend on how warm it is in your room, and whether your MacBook Air sits directly under a fan.

      • jsheard 22 minutes ago

        Apple chips are very good especially for their power envelope but let's not get ahead of ourselves, the only way a Macbook Air feels competitive with a top-of-the-line desktop is if you're not actually utilizing the full sustained power of the desktop. There's a reason why Apple sells much bigger Max/Ultra chips with active cooling.

        • freeone3000 5 minutes ago

          It’s still a lot less active cooling - the MBP fan and fan noise is noticably less than every thinkpad I’ve had, and its perf beats most desktop i7s.

    • throwa356262 35 minutes ago

      First of all, Apple CPUs are not the fastest. In fact top 20 fastest CPUs right now is probably an AMD and Intel only affair.

      Apples CPUs are most powerful efficient however, due to a bunch of design and manufacturing choices.

      But to answer your question, yes Windows 11 with modern security crap feels 2-3 slower than vanilla Linux on the same hardware.

      • ksec 2 minutes ago

        >First of all, Apple CPUs are not the fastest. In fact top 20 fastest CPUs right now is probably an AMD and Intel only affair.

        You are comparing 256 AMD Zen6c Core to What? M4 Max?

        When people say CPU they meant CPU Core, And in terms of Raw Speed, Apple CPU holds the fastest single core CPU benchmarks.

      • nerdsniper 13 minutes ago

        I do believe Apple are still the fastest single-core (M5, A19 Pro, and M3 Ultra leading), which still matters for a shocking amount of my workloads. But only the M5 has any noticeable gap vs Intel (~16%). Also the rankings are a bit gamed because AMD and Intel put out a LOT of SKU's that are nearly the same product, so whenever they're "winning" on a benchmark they take up a bunch of slots right next to eachother even though they're all basically the exact same chip.

      • rahkiin 30 minutes ago

        My windows with corporate crap is sometimes 2000x slower than without corporate crap. And consistently 10x slower than an M3

        • PaulHoule 19 minutes ago

          I was impressed with my M4 mini when I got it a year ago but sometime after the Liquid Glass update it is now: beachball… beachball… beachball… reboot… beachball… beachball… Reminds me of the bad old days of Win XP.

          • nerdsniper 2 minutes ago

            How much RAM do you have? That seems to be the main thing that slows down my MacBooks (original launch-day 16GB M1 MBP and 32 GB M2 Pro)

      • vachina 21 minutes ago

        My RHEL vnc feels snappier than the Windows 11 client it’s running on.

        With maximum corporate spyware it consistently takes 1 second to get a visual feedback on Windows.

      • ajross 12 minutes ago

        > First of all, Apple CPUs are not the fastest.

        The cores are. Nothing is beating a M4/M5 on single CPU performance, and per-cycle nothing is even particularly close.

        At the whole-chip level, there are bigger devices from the x86 vendors which will pull ahead on parallel benchmarks. And Apple's unfortunate allergy to effective cooling techniques (like, "faster fans move more air") means that they tend to throttle on chip-scale loads[1].

        But if you just want to Run One Thing really fast, which even today still correlates better to "machine feels fast" than parallel loads, Apple is the undisputed king.

        [1] One of the reasons Geekbench 6, which controversially includes cooling pauses, looks so much better for Apple than version 5 did.

        • gpderetta 3 minutes ago

          It doesn't really make much sense to compare per-cycle performance across microarchitectures as there are multiple valid trade-offs.

          Of course Apple did pick a very good sweet spot favoring a wide core as opposed to a speed daemon more than the competition.

    • rngfnby 17 minutes ago

      New Mac arm user here.

      Replaced a good Windows machine (Ryzen 5? 32 Gb) and I have a late intel Mac and a Linux workstation (6 core Ryzen 5, 32 Gb).

      Obviously the Mac is newer. But wow. It's faster even on things that CPU shouldn't matter, like going through a remote samba mount through our corporate VPN.

      - Much faster than my intel Mac

      - Faster than my Windows

      - Haven't noticed any improvements over my Linux machines, but with my current job I no longer get to use them much for desktop (unfortunately).

      Of course, while I love my Debian setup, boot up is long on my workstation; screensaver/sleep/wake up is a nightmare on my entertainment box (my fault, but common!). The Mac just sleeps/wakes up with no problems.

      The Mac (smallest air) is also by far the best laptop Ive ever had from a mobility POV. Immediate start up, long battery, decent enough keyboard (but If rather sacrifice for a longer keypress)

    • cj 39 minutes ago

      For me it’s things like boot speed. How long does it take to restart the computer. To log out, and log back in with all my apps opening.

      Mac on intel feels like it was about 2x slower at these basic functions. (I don’t have real data points)

      Intel Mac had lag when opening apps. Silicon Mac is instant and always responsive.

      No idea how that compares to Linux.

      • throwa356262 4 minutes ago

        Some of that can be attributed to faster IO.

        Something else to consider: chromebook on arm boots significantly faster than dito intel. Yes, nowadays Mediateks latest cpus wipe the floor with intel N-whatever, but it has been like this since the early days when the Arm version was relatively underpowered.

        Why? I have no idea.

      • nerdsniper 18 minutes ago

        Windows can boot pretty fast these days, I'm always surprised by it. I run LTSC on mine though, so zero bloat. Both my Macs and Windows LTSC have quick boots nowadays, I'm not sure I could say which is faster, but it might be the Windows.

      • eru 22 minutes ago

        Well, completely rebooting is a lot slower on my Macs than on my Linux.

        But I'm running a fairly slim Archlinux install without a desktop environment or anything like that. (It's just XMonad as a window manager.)

      • nottorp 27 minutes ago

        Hmm? Why do you restart your computer often enough to notice?

        Even Windows (or at least my install that doesn't have any crap besides visual studio on it) can run for weeks these days...

    • newsclues 39 minutes ago

      Power management with Mac’s is the big benefit, imo.

      It’s all about the perf per watt.

  • ricardobeat 41 minutes ago

    > The fact that an idle Mac has over 2,000 threads running in over 600 processes is good news

    Not when one of those decides to wreck havoc - spotlight indexing issues slowly eating away your disk space, icloud sync spinning over and over and hanging any app that tries to read your Documents folder, Photos sync pegging all cores at 100%… it feels like things might be getting a little out of hand. How can anyone model/predict system behaviour with so many moving parts?

    • hmokiguess 17 minutes ago

      for me it’s iMessage, it gets out of sync way too often and then it eats the CPU away

      • sgt a minute ago

        Pretty heavy iMessage user here, but I can't say I experience any issues, and that's probably why your issue is not getting fixed - ie. nobody at Apple is able to reproduce it. Maybe you should gather some info about it and see if you can send a bug report?

    • fragmede 38 minutes ago

      and if it paid off, that would almost be acceptable! But no. After spotlight has indexed my /Applications folder, when I hit command-spacebar and type "preview.app", it takes ~4 seconds on my M4 laptop to search the sqlite database for it and return that entry.

      grumble

      • tambourine_man 32 minutes ago

        I may be a spotlight unicorn, but I’ve never seen this behavior people complain about. Spotlight has always been instant for me, since its introduction and I’ve never seen a regression.

        It is completely useless on network mounts, however, where I resort to find/grep/rg

      • etrvic 30 minutes ago

        On my Intel mac searching with cmd+space for a file takes under a second. Maybe there is a problem on your end?

        • ricardobeat 26 minutes ago

          I’ve actually had worse problems as recently as last week: Apps stopped showing up completely in spotlight.

          Only a system reinstall + manually deleting all index files fixed it. Meanwhile it was eating 20-30GB of disk space. There are tons of reports of this in the apple forums.

          Even then, it feels a lot slower in MacOS 26 than it did before, and you often get the rug-pull effect of your results changing a millisecond before you press the enter key. I would pay good money to go back to Snow Leopard.

          • etrvic 16 minutes ago

            I had the same problem last year, re-indexing all the files fixed it for me[1].

            That being said, macOS was definitely more snappy back on Catalina, which was the first version I had so I can't vouch for Snow Leopard. Each update after Catalina felt gradually worse and from what i heard Tahoe feels like the last nail in the coffin.

            I hope the UX team will deliver a more polished, expressive and minimal design next time.

            [1] - https://support.apple.com/en-us/102321

      • admissionsguy 36 minutes ago

        TIL there is a search bar triggered by CMD+Space. After 15 long years.

        • rngfnby 24 minutes ago

          Too late. Apple has destroyed it.

          I just got my first ARM Mac to replace my work Win machine (what has MS done to Windows!?!? :'()

          Used to be I could type "display" and Id get right to display settings in settings. Now it shows thousands of useless links to who knows what. Instead I have to type "settings" and then, within settings, type "display"

          Still better than the Windows shit show.

          Honestly, a well setup Linux machine has better user experience than anything on the market today.

  • sys_64738 2 minutes ago

    My M2 MBA doesn't have a fan but literally smokes the majority on Intel systems which are space heaters this time of year. Those legacy x86 apps don't really exist for the majority of people anymore.

  • tyleo 2 hours ago

    These processors are good all around. The P cores kick butt too.

    I ran a performance test back in October comparing M4 laptops against high-end Windows desktops, and the results showed the M-series chips coming out on top.

    https://www.tyleo.com/blog/compiler-performance-on-2025-devi...

    • murderfs an hour ago

      This is likely more of a Windows filesystem benchmark than anything else: there are fundamental restrictions on how fast file access can be on Windows due to filesystem filter drivers. I would bet that if you tried again with Linux (or even in WSL2, as long as you stay in the WSL filesystem image), you'd see significantly improved results.

    • etrvic 34 minutes ago

      From your article it seems like you benchmark compile times. I am not an expert on the subject, but I don't see the point in comparing ARM compilation times with Intel. There are probably different tricks involved in compilation and the instructions set are not the same.

    • cubefox 44 minutes ago

      Here is a more recent comparison with Intel's new Panther Lake chips: https://www.tomsguide.com/computing/cpus/panther-lake-is-int...

      • sys_64738 3 minutes ago

        Are the Intel systems plugged in when running those tests? Usually when Apple machines do the tests then the difference between battery/plugged in is small if any.

  • amelius 31 minutes ago

    That's just framing. A different wording could be: by moving more work to slow (but power efficient) cores, the other cores (let's call them performance cores) are free to do other stuff.