3 ms·

This isn't a phone CPU though, it's a laptop CPU, and most laptops have batteries that are literally bigger than your entire phone. So an extra 3 watts isn't su

This isn't a phone CPU though, it's a laptop CPU, and most laptops have batteries that are literally bigger than your entire phone. So an extra 3 watts isn't such a big difference. The real problem isn't actually the power-draw while working though. Where x86 processors run into real battery life trouble is that modern Windows and Linux are really bad about keeping power draw low when the laptop lid is closed. You can put your phone to sleep and leave it for a couple days and find its only lost 10% battery life, but if you close a Linux or Windows laptop and leave it for a couple days without actually powering it off, you're typically looking at something more like 50% battery life lost. This is the real problem that needs to be solved, and it's going to be quite difficult because it'll involve hunting down tonnes of super old crufty low-level OS code and redesigning it. One of the biggest reason ARM laptops tend to not have this problem is that a ton of low-level OS stuff had to be totally rewritten for them, so they just did the efficient thing in the first place, rather than having to sift through existing, working code and tweak it for better efficiency.

ranguna 2y ago
8w vs 5w power would make your battery time jump from 12h to 19h. When looked at alone 3w difference is not a lot, but in the context of 8w to 3w, 3w is an improvement of around 37% (if I did the math right). If you optimize the software in such a way that the power draw on idle can be very low, all that work will go to waste if the cpu is clocked at 8w minimum. You need a cpu that supports going to that low wattage. Taking this as a reference for an arm cpu on a laptop: https://www.anandtech.com/show/17024/apple-m1-max-performance-review/3 https://www.anandtech.com/show/17024/apple-m1-max-performanc... You can see that even with the laptop on showing a static screen, the power draw is less than 1W. That's crazy and tbh, I'm not sure I believe it myself. In summary, I do agree with you that we need to optimize our OSs so that they become more efficient, but we also need the hardware to improve. 8w minimum is not nearly enough for good battery life.
- delfinom 2y ago
  It's only less than 1W for the CPU, the total consumption is 7.2W at idle because the screen is going to suck power no matter what. Per the table at the end. Existing Intel Meteor Lake CPU in laptops already draw anywhere from 4W to 11W idle (That's CPU + screen in benchmarks). Like these: https://www.notebookcheck.net/Xiaomi-RedmiBook-Pro-16-2024-review-Perhaps-the-best-Meteor-Lake-laptop-with-a-long-battery-life.829901.0.html#c11198005 https://www.notebookcheck.net/Xiaomi-RedmiBook-Pro-16-2024-r...
  - ranguna 2y ago
    Indeed, but a win on the cpu power consumption is a win, regardless if you have other stuff sucking power or not.
lxgr 2y ago
> Where x86 processors run into real battery life trouble is that modern Windows and Linux are really bad about keeping power draw low when the laptop lid is closed. That power draw has nothing to do with the CPUs power efficiency, though: Laptop lid closed usually means S3, though, and the CPU is completely unpowered in that state. (CPU registers are saved to RAM.) The biggest power draw in S3 is the RAM itself, which has to be continuously refreshed to not lose its data, but that can be avoided by doing suspend-to-disk instead. Modern systems usually do some hybrid between the two, e.g. suspend to both RAM and disk, and power off the RAM after a few hours (or at a given battery level) to meet a compromise between resume speed and battery life.
- The_Colonel 2y ago
  Unfortunately, modern Windows laptops don't support S3 sleep, instead they have this Modern Standby where CPU runs in low power all the time.
  - beart 2y ago
    It's really bad. I've never been able to keep a dell laptop asleep. If I don't shut it down completely before putting it into my bag, it will surely be too hot to touch when I pull it back out. Super frustrating when traveling. Flabbergasting, that this issue has not been addressed.
    - lxgr 2y ago
      Wow, I had no idea! When I last used Linux and Windows on a Thinkpad, lid closed was equivalent to S3, as indicated by the little crescent moon LED on the lid, fans out, and the battery in that state would last for several days. My Mac does occasionally turn on with the lid closed to do "useful background tasks" (not actually that useful to me, except for broadcasting "Find my Mac" via Bluetooth), but except for one time when I accidentally had that option permanently flagged one via some "prevent sleep" app (I only found out when I noticed that I could SSH to my laptop while it was in my backpack!), it hasn't noticeably drained my battery.
- 2y ago

ranguna 2y ago

8w vs 5w power would make your battery time jump from 12h to 19h. When looked at alone 3w difference is not a lot, but in the context of 8w to 3w, 3w is an improvement of around 37% (if I did the math right). If you optimize the software in such a way that the power draw on idle can be very low, all that work will go to waste if the cpu is clocked at 8w minimum. You need a cpu that supports going to that low wattage. Taking this as a reference for an arm cpu on a laptop: https://www.anandtech.com/show/17024/apple-m1-max-performance-review/3 https://www.anandtech.com/show/17024/apple-m1-max-performanc... You can see that even with the laptop on showing a static screen, the power draw is less than 1W. That's crazy and tbh, I'm not sure I believe it myself. In summary, I do agree with you that we need to optimize our OSs so that they become more efficient, but we also need the hardware to improve. 8w minimum is not nearly enough for good battery life.

delfinom 2y ago
It's only less than 1W for the CPU, the total consumption is 7.2W at idle because the screen is going to suck power no matter what. Per the table at the end. Existing Intel Meteor Lake CPU in laptops already draw anywhere from 4W to 11W idle (That's CPU + screen in benchmarks). Like these: https://www.notebookcheck.net/Xiaomi-RedmiBook-Pro-16-2024-review-Perhaps-the-best-Meteor-Lake-laptop-with-a-long-battery-life.829901.0.html#c11198005 https://www.notebookcheck.net/Xiaomi-RedmiBook-Pro-16-2024-r...
- ranguna 2y ago
  Indeed, but a win on the cpu power consumption is a win, regardless if you have other stuff sucking power or not.

lxgr 2y ago

> Where x86 processors run into real battery life trouble is that modern Windows and Linux are really bad about keeping power draw low when the laptop lid is closed. That power draw has nothing to do with the CPUs power efficiency, though: Laptop lid closed usually means S3, though, and the CPU is completely unpowered in that state. (CPU registers are saved to RAM.) The biggest power draw in S3 is the RAM itself, which has to be continuously refreshed to not lose its data, but that can be avoided by doing suspend-to-disk instead. Modern systems usually do some hybrid between the two, e.g. suspend to both RAM and disk, and power off the RAM after a few hours (or at a given battery level) to meet a compromise between resume speed and battery life.

The_Colonel 2y ago
Unfortunately, modern Windows laptops don't support S3 sleep, instead they have this Modern Standby where CPU runs in low power all the time.
- beart 2y ago
  It's really bad. I've never been able to keep a dell laptop asleep. If I don't shut it down completely before putting it into my bag, it will surely be too hot to touch when I pull it back out. Super frustrating when traveling. Flabbergasting, that this issue has not been addressed.
  - lxgr 2y ago
    Wow, I had no idea! When I last used Linux and Windows on a Thinkpad, lid closed was equivalent to S3, as indicated by the little crescent moon LED on the lid, fans out, and the battery in that state would last for several days. My Mac does occasionally turn on with the lid closed to do "useful background tasks" (not actually that useful to me, except for broadcasting "Find my Mac" via Bluetooth), but except for one time when I accidentally had that option permanently flagged one via some "prevent sleep" app (I only found out when I noticed that I could SSH to my laptop while it was in my backpack!), it hasn't noticeably drained my battery.
2y ago