6 ms·

Did someone do a deep dive on why battery life is so awful on Linux? Or is it some Ashai's driver's inefficiencies that causing this?

temp0826 10mo ago
This is the case with most (all?) laptops running Linux regardless of hardware unfortunately.
- fsh 10mo ago
  This doesn't match my experience. My previous three laptops (two AMD Lenovo Thinkpads, one Intel Sony VAIO) had essentially the same battery life running Linux as running Windows.
  - martini333 10mo ago
    I think MacOS was implied...
    - olyjohn 10mo ago
      Have you ever put MacOS on a PC laptop? Terrible hardware support and the worst battery life of any OS.
      - functionmouse 10mo ago
        I used to hackintosh every laptop I could get my hands on that could do it, and always saw better battery life on OS X vs. Windows.
  - sincerely 10mo ago
    I have an AMD thinkpad and get maybe 1/4 the battery life on Linux as I do when I boot inti Windows, did you have to do any tweaking to achieve that?
    - fsh 10mo ago
      I typically install and enable tlp [1], but that's it. Some distros/DEs might have it out of the box, but on Arch I had to do it myself. [1] https://wiki.archlinux.org/title/TLP https://wiki.archlinux.org/title/TLP
      - cromka 10mo ago
        TLP, as mentioned. Also powertop for more in-depth view of what's happening on power consumption front.
  - functionmouse 10mo ago
    You're lucky, my thinkpad x13 gen 2 AMD gets 5 hours on modern Fedora vs. 9 or 10 on Windows.
    - maxhille 10mo ago
      I also have an X13 Gen2 AMD. My idle power consumption is 2.5W to 4W depending on brightness. This ends up in 12h-15h (machine/battery ist 2y old I think). I think you can improve your power settings.
  - gf000 10mo ago
    Does that mean that Windows's battery life suck equally on these devices?
izacus 10mo ago
Each controller and subcomponent on the motherboard needs a driver that correctly puts it into low power and sleep states to get battery savings. Most of those components are proprietary and don't use the standard drivers available in Linux kernel. So someone needs to go and reverse engineer them, upstream the drivers and pray that Apple doesn't change them in next revision (which they did) or the whole process needs to start again. In other words: get an actually Linux supported laptop for Linux.
- Forgeties79 10mo ago
  >In other words: get an actually Linux supported laptop for Linux. For a lot of people the point is to extend the life of their already-purchased hardware.
  - bigyabai 10mo ago
    1. Linux isn't a panacea for depreciated hardware, and it never will be. 2. If your priority is system lifespan, you are already using OEM macOS.
    - Forgeties79 10mo ago
      Never said it was “panacea for depreciated hardware.” I’m saying it’s a common use case. Every thread about Linux inevitably someone says “it gave new life to my [older computer model].” We’ve all seen it countless times.
      - Forgeties79 10mo ago
        And there it is: https://news.ycombinator.com/item?id=46387364 https://news.ycombinator.com/item?id=46387364
        bigyabai 10mo ago
        It's a common use-case for x86 machines that implement UEFI. Taking the iPhone and iPad into account, it is a nonexistent use-case for mobile ARM chipset owners.
paddim8 10mo ago
It absolutely is not awful. You are doing something wrong then. It's not as good as on macOS of course but it's still great. I get 8-10 hours.
- imiric 10mo ago
  Exactly. This myth keeps being perpetuated, for some reason. I'm typing this from a ThinkPad X1 Carbon Gen 13 running Void Linux, and UPower is reporting 99% battery with ~15h left. I do have TLP installed and running, which is supposed to help. Realistically, I won't get around 15h with my usage patterns, but I do get around 10-12 hours. It's a new laptop with a fresh battery, so that plays a big role as well. This might not be as good as the battery life on a Macbook, but it's pretty acceptable to me. The upcoming Intel chips also promise to be more power efficient, which should help even more.
- mort96 10mo ago
  Eh it's pretty awful. I get 8 hours, yes, but in Linux, those 8 hours are ticking whether my laptop is sleeping in my bag or on my desk with the lid closed or I'm actively using it. 8 hours of active use is pretty good, but 8 hours in sleep is absolutely dreadful.
dllu 10mo ago
Apple does tons of optimizations for every component to improve battery life. Asahi Linux, which is reverse engineered, doesn't have the resources to figure out each of those tricks, especially for undocumented proprietary hardware, so it's a "death by a thousand cuts" as each of the various components is always drawing a couple of milliwatts more than on macOS.
bjackman 10mo ago
For optimal battery life you need to tweak the whole OS stack for the hardware. You need to make sure all the peripherals are set up right to go into the right idle states without causing user-visible latency on wake-up. (Note that often just one peripheral being out of tune here can mess up the whole system's power performance. Also the correct settings here depend on your software stack). You need to make sure that cpufreq and cpuidle governors work nicely with the particular foibles of your platform's CPUs. Ditto for the task scheduler. Then, ditto for a bunch of random userspace code (audio + rendering pipeline for example). The list goes on and on. This work gets done in Android and ChromeOS.
CamouflagedKiwi 10mo ago
Asahi doesn't yet support all the CPU power states etc. This is a known limitation, not sure how easy it is to reverse engineer though.

temp0826 10mo ago

This is the case with most (all?) laptops running Linux regardless of hardware unfortunately.

fsh 10mo ago
This doesn't match my experience. My previous three laptops (two AMD Lenovo Thinkpads, one Intel Sony VAIO) had essentially the same battery life running Linux as running Windows.
- martini333 10mo ago
  I think MacOS was implied...
  - olyjohn 10mo ago
    Have you ever put MacOS on a PC laptop? Terrible hardware support and the worst battery life of any OS.
    - functionmouse 10mo ago
      I used to hackintosh every laptop I could get my hands on that could do it, and always saw better battery life on OS X vs. Windows.
- sincerely 10mo ago
  I have an AMD thinkpad and get maybe 1/4 the battery life on Linux as I do when I boot inti Windows, did you have to do any tweaking to achieve that?
  - fsh 10mo ago
    I typically install and enable tlp [1], but that's it. Some distros/DEs might have it out of the box, but on Arch I had to do it myself. [1] https://wiki.archlinux.org/title/TLP https://wiki.archlinux.org/title/TLP
    - cromka 10mo ago
      TLP, as mentioned. Also powertop for more in-depth view of what's happening on power consumption front.
- functionmouse 10mo ago
  You're lucky, my thinkpad x13 gen 2 AMD gets 5 hours on modern Fedora vs. 9 or 10 on Windows.
  - maxhille 10mo ago
    I also have an X13 Gen2 AMD. My idle power consumption is 2.5W to 4W depending on brightness. This ends up in 12h-15h (machine/battery ist 2y old I think). I think you can improve your power settings.
- gf000 10mo ago
  Does that mean that Windows's battery life suck equally on these devices?

izacus 10mo ago

Each controller and subcomponent on the motherboard needs a driver that correctly puts it into low power and sleep states to get battery savings. Most of those components are proprietary and don't use the standard drivers available in Linux kernel. So someone needs to go and reverse engineer them, upstream the drivers and pray that Apple doesn't change them in next revision (which they did) or the whole process needs to start again. In other words: get an actually Linux supported laptop for Linux.

Forgeties79 10mo ago
>In other words: get an actually Linux supported laptop for Linux. For a lot of people the point is to extend the life of their already-purchased hardware.
- bigyabai 10mo ago
  1. Linux isn't a panacea for depreciated hardware, and it never will be. 2. If your priority is system lifespan, you are already using OEM macOS.
  - Forgeties79 10mo ago
    Never said it was “panacea for depreciated hardware.” I’m saying it’s a common use case. Every thread about Linux inevitably someone says “it gave new life to my [older computer model].” We’ve all seen it countless times.
    - Forgeties79 10mo ago
      And there it is: https://news.ycombinator.com/item?id=46387364 https://news.ycombinator.com/item?id=46387364
      - bigyabai 10mo ago
        It's a common use-case for x86 machines that implement UEFI. Taking the iPhone and iPad into account, it is a nonexistent use-case for mobile ARM chipset owners.

paddim8 10mo ago

It absolutely is not awful. You are doing something wrong then. It's not as good as on macOS of course but it's still great. I get 8-10 hours.

imiric 10mo ago
Exactly. This myth keeps being perpetuated, for some reason. I'm typing this from a ThinkPad X1 Carbon Gen 13 running Void Linux, and UPower is reporting 99% battery with ~15h left. I do have TLP installed and running, which is supposed to help. Realistically, I won't get around 15h with my usage patterns, but I do get around 10-12 hours. It's a new laptop with a fresh battery, so that plays a big role as well. This might not be as good as the battery life on a Macbook, but it's pretty acceptable to me. The upcoming Intel chips also promise to be more power efficient, which should help even more.
mort96 10mo ago
Eh it's pretty awful. I get 8 hours, yes, but in Linux, those 8 hours are ticking whether my laptop is sleeping in my bag or on my desk with the lid closed or I'm actively using it. 8 hours of active use is pretty good, but 8 hours in sleep is absolutely dreadful.

dllu 10mo ago

Apple does tons of optimizations for every component to improve battery life. Asahi Linux, which is reverse engineered, doesn't have the resources to figure out each of those tricks, especially for undocumented proprietary hardware, so it's a "death by a thousand cuts" as each of the various components is always drawing a couple of milliwatts more than on macOS.

bjackman 10mo ago

For optimal battery life you need to tweak the whole OS stack for the hardware. You need to make sure all the peripherals are set up right to go into the right idle states without causing user-visible latency on wake-up. (Note that often just one peripheral being out of tune here can mess up the whole system's power performance. Also the correct settings here depend on your software stack). You need to make sure that cpufreq and cpuidle governors work nicely with the particular foibles of your platform's CPUs. Ditto for the task scheduler. Then, ditto for a bunch of random userspace code (audio + rendering pipeline for example). The list goes on and on. This work gets done in Android and ChromeOS.

CamouflagedKiwi 10mo ago

Asahi doesn't yet support all the CPU power states etc. This is a known limitation, not sure how easy it is to reverse engineer though.