[solved] How to disable hyper-threading

nugetchar · 2014-08-10 17:28:14

Hi

I've got a DELL latitude E6430 with a Intel Core i7 (quadri-core). My kernel version is Linux 3.15.8-1.
I noticed that my machine was actually working with hyper-threading thanks to the htop command which prints 8 cores. I don't need 8 cores, and I would like to improve my battery life instead. So my question is quite simple : How can I disable hyper-threading for all my cores, and is it possible to disable it for only two of them?

Last edited by nugetchar (2014-08-11 12:49:37)

ANOKNUSA · 2014-08-10 17:44:31

It's controlled at the firmware level, from the motherboard setup menu. But you probably aren't going to get any more battery life than you've already got. The kernel handles Intel CPU throttling and process management automatically, and tries to maximize efficiency on its own. You can't disable the physical cores anyway. You can give it a shot, but you almost certainly won't notice any difference.

nugetchar · 2014-08-10 17:49:15

Mmmh okay, well I trust you, I don't want to risk to do something dirty for nothing. Thanks anyway

ANOKNUSA · 2014-08-10 18:41:59

It's not "dirty;" you just reboot, open the system settings menu (press Esc or F2 or whatever) and find the option to turn off hyperthreading. It won't hurt anything, I just suspect it won't help extend your battery life either.

nugetchar · 2014-08-10 22:26:26

Okay so I tried and it changes nothing. The problem is my battery is this model. According to my laptop watt-consumption and the fact that this battery supplies 97Whr, it should last at least more than 7 hours. It barely lasts 3 hours...

Well I have to unmark this topic solved because now, I have to face a problem I cannot explain : why does this battery lasts only 3 hours?

I thought it could be a hardware problem, but I don't know how to be sure. For information, ma battery is 1 y.o...

Pse · 2014-08-11 02:39:12

You should probably go over this wiki entry to see if you can get any improvements:

https://wiki.archlinux.org/index.php/Power_saving

SilverOne · 2014-08-11 02:46:41

well does your computer have two graphic cards? i have a macbook pro and get around 5 hours with the intel gpu and maybe 2 ~ 3 with the amd gpu.

nugetchar · 2014-08-11 12:49:24

@Pse : thanks, I'm currently reading it.
@SilverOne : yes, and I ue an nVidia card with the Optimus technology.

But don't worry guys, I managed to gain like 2 or 3 hours of autonomy by modifying some settings in the setup menu.

Arch Linux

#1 2014-08-10 17:28:14

[solved] How to disable hyper-threading

#2 2014-08-10 17:44:31

Re: [solved] How to disable hyper-threading

#3 2014-08-10 17:49:15

Re: [solved] How to disable hyper-threading

#4 2014-08-10 18:41:59

Re: [solved] How to disable hyper-threading

#5 2014-08-10 22:26:26

Re: [solved] How to disable hyper-threading

#6 2014-08-11 02:39:12

Re: [solved] How to disable hyper-threading

#7 2014-08-11 02:46:41

Re: [solved] How to disable hyper-threading

#8 2014-08-11 12:49:24

Re: [solved] How to disable hyper-threading

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