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Comment by akho | Hacker News Reader

x12 and x6 do not seem plausible. Something is very wrong.

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

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.

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.

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.

> would imply <1h runtime, or a >50W consumption at idle

That's the case.

My CPU is at over 5GHz, 1% load and 70C at the moment. That's in a "power-saving mode".

If nothing would be wrong, it'd be at something like 1.5GHz with most of the cores unpowered.

What is the laptop, and what's it doing?

Something is wrong with power governor then. I have an opposite experience, was able to tune Linux on a Core Ultra 155H laptop so it works longer than Windows one. Needed to use kernel 6.11+ and TLP [0] with pretty aggressive energy saving settings. Also played a bit with Intel LPMD [1] but did not notice much improvement.

[0] https://github.com/linrunner/TLP

[1] https://github.com/intel/intel-lpmd

I also own a 155H laptop using Linux Mint! Would you share your settings with TLP and LPMD? I am not getting not much longer battery life than Windows 11 on it after some tinkering, so seeing somebody else's setup may help a lot. Thanks!

Won't say I got much longer battery life, and even what I got may be as well explained as "TLP made energy profile management almost as good as on Windows, and then Windows's tendency to get a bunch of junk processes seeping on your battery tipped the scales to favor Linux". Also I ended up switching back to Windows because of never-ending hardware issues with Linux, installing it on 155H back in February 2024 was especially rough but even 6 months later I randomly got Bluetooth not working anymore after Ubuntu update.

My TLP and LPMD configs: https://gist.github.com/vient/f8448d56c1191bf6280122e7389fc1...

TLP: don't remember details now, as I recall scaling governor does not do anything on modern CPUs when energy perf policy is used. CPU_MAX_PERF_ON_BAT=30 seems to be crucial for battery savings, sacrificing performance (not too much for everyday use really) for joules in battery. CPU_HWP_DYN_BOOST_ON_BAT=0 further prohibits using turbo on battery, just in case.

LPMD: again, did not use it much in the end so not sure what even is written in this config. May need additional care to run alongside TLP.

Also, I used these boot parameters. For performance, I think, beneficial one are *mitigations, nohz_full, rcu*

    quiet splash sysrq_always_enabled=1 mitigations=off i915.mitigations=off transparent_hugepage=always iommu=pt intel_iommu=on nohz_full=all rcu_nocbs=all rcutree.enable_rcu_lazy=1 rcupdate.rcu_expedited=1 cryptomgr.notests no_timer_check noreplace-smp page_alloc.shuffle=1 tsc=reliable

What p-state driver are you using?

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