Arch Linux

Porost

Member

Registered: 2011-09-22

Posts: 9

[SOLVED] External USB mouse causes very high CPU load

Hello,

this is far from a scientific test, but if I launch a cpu load monitor and wiggle the mouse cursor over it with the built-in touchpad, the CPU load goes up by 3-4%. When I do the same with a USB mouse, it's 30-40%. Also, in a 3D game, moving the camera around with the touchpad drops the FPS from 35 to 25, while doing the same with the USB mouse drops it to about 5-10 FPS, so something is definetely wrong here.

If I don't touch the mouse, it doesn't produce any load.

The CPU load comes from both X and the window over which I am wiggling the cursor, whether it is a terminal, browser or whatever, with the window contributing about 2/3 of it. If I don't do it over a window, the excessive load comes only from X and is much smaller (but still several times bigger than the load the touchpad produces).

I have no idea how to even tackle the issue.

I run Arch 64, on an Asus 1201N laptop. The mouse is Logitech G5 (laser mouse).

Last edited by Porost (2011-09-23 19:36:04)

lilsirecho

Veteran

Registered: 2003-10-24

Posts: 5,000

Re: [SOLVED] External USB mouse causes very high CPU load

If the mouse is wiggled across items on the display that have active addresses it is quite normal for the system to respond as you report. 

Test the response when wiggling it across text and see the difference.

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Porost

Member

Registered: 2011-09-22

Posts: 9

Re: [SOLVED] External USB mouse causes very high CPU load

I don't think so. The issue here is the order-of-magnitude difference between doing exactly the same thing with a touchpad and with an external mouse, not the absolute load produced by it.

And the test has been done over text anyway.

Last edited by Porost (2011-09-23 09:37:33)

rwd

Member

Registered: 2009-02-08

Posts: 664

Re: [SOLVED] External USB mouse causes very high CPU load

Have you tried with a different mouse, to check if it is specific to this mouse /driver? Does lowering the polling rate help? (https://wiki.archlinux.org/index.php/Mouse_Polling_Rate) .I remember vaguely that laptop mode caused this too.. search the forums for mouse and cpu.

Last edited by rwd (2011-09-23 19:24:30)

Porost

Member

Registered: 2011-09-22

Posts: 9

Re: [SOLVED] External USB mouse causes very high CPU load

Oooh, thanks! Seems that the mouse, being a gaming mouse, had some crazy pooling rate set. Lowering it fixed the problem!

Marking as solved, thank you.

Last edited by Porost (2011-09-23 19:44:09)