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dors

Member

Registered: 2020-04-08

Posts: 21

[SOLVED] Idle Intel power consumption very high

I have a Dell inspiron 15 5000 with an i7 8565U and an Nvidia mx 150. I have installed both nvidia and intel drivers, as well as optimus-manager. I am currently running on intel graphics (this is what I set with optimus-manager), and monitoring the power consumption with PowerTOP.

I notice a quite high TDP when in idle, of around 14-17 W with brightness at miniumm with peaks as high as 25W and never lower than 11W. 

On Device stats I see that the device using most of the Power is my CPU, with 14 W between cpu-core and cpu-misc

I have run powertop --calibrate so in theory this numbers should be accurate.

I am also noticing that on average my cores run at around 3.0 GhZ, although I don't have any application open.

I suspect it might have to do with nvidia and/or nvidia-optimus, as I installed those drivers two days ago and I noticed from that moment that my laptop battery would discharge way quicker.  I am talking from 70% to 35% of batter in ~1 hour with just a couple of terminal applications going (such as powertop).

Is there something I should do to decrease the TdP?

Thanks

Last edited by dors (2020-04-23 10:07:09)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,384

Re: [SOLVED] Idle Intel power consumption very high

Which configuration did you do to handle/disable the nvidia card while not in use? Optimus-manager can help you here, but it does not do anything by default:  https://github.com/Askannz/optimus-mana … nt-options

On a side-note, as you have a card this new you could also completely remove optimus-manager and instead make use of https://wiki.archlinux.org/index.php/PR … er_offload for dynamic access to the nvidia card including proper power management.

Last edited by V1del (2020-04-23 09:22:12)

dors

Member

Registered: 2020-04-08

Posts: 21

Re: [SOLVED] Idle Intel power consumption very high

at the moment, I just run 

 optimus-manager --switch intel

just to be sure I am using only intel. I have not configured anything yet.

Last edited by dors (2020-04-23 09:27:27)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,384

Re: [SOLVED] Idle Intel power consumption very high

Yes and optimus-manager will set that up, but the nvidia card will keep on trucking at "full" blast, because optimus-manager explicitly expects you to make a decision on which power management method should be used to disable the nvidia card, as due to historic/HW setup reasons there are multiple ways to achieve it.

If you don't need external monitors, the "best" would be to opt for nvidia-prime (and removing optimus-manager as it's mostly superfluous in that case) otherwise read the relevant linked instructions.

Last edited by V1del (2020-04-23 09:34:57)

dors

Member

Registered: 2020-04-08

Posts: 21

Re: [SOLVED] Idle Intel power consumption very high

Ok so I removed as you suggested optimus-manager and I created a file under /etc/X11 named xorg.conf (there wasn't any file before) where I pasted the instructions provided by the second link you provided and rebooted. The idle power management now seems to have lowered to 9.75/10 W which I think it is more or less normal.

I have read a bit the documentation but I am not sure I understood. After I patch xorg.conf, shall I expect that the system automatically switches between discrete and integrated graphic cards, without me having to do nothing, right? For instance I would like that on boot the default card to be the nvidia one, as I noticed that with intel booting takes 10 seconds more, and then that the system understands which graphic card enable. Do I need to set all of this up?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,384

Re: [SOLVED] Idle Intel power consumption very high

Install the nvidia-prime package. When you come across an application that you need more oomph on, run said application with

prime-run $application

dors

Member

Registered: 2020-04-08

Posts: 21

Re: [SOLVED] Idle Intel power consumption very high

Thank you for your reply, now I got it. So basically I asked the system to always use the integrated card, unless I specify that I want the application to be run with nvidia. I guess I can put aliases to applications that I always want to start with nvidia (such as games) and stuff like that. I mark it as solved.