Comments on: iwm(4) and power management https://www.dragonflydigest.com/2016/10/10/iwm4-and-power-management/ A running description of activity related to DragonFly BSD. Mon, 10 Oct 2016 19:36:54 +0000 hourly 1 https://wordpress.org/?v=7.0 By: Imre Vadász https://www.dragonflydigest.com/2016/10/10/iwm4-and-power-management/comment-page-1/#comment-469802 Mon, 10 Oct 2016 19:36:54 +0000 https://www.dragonflydigest.com/?p=18758#comment-469802 I did some power measurements with my hp x2 210 detachable (with AC3165 chipset), using a (still experimental) driver to read the battery discharge rate.
Enabling powersaving in iwm(4) via ifconfig and setting the hw.iwm.power_scheme=3 tunable, lowers power usage by ca. 0.25 W. So enabled wlan only seems to use ca. 50-100 mW then.
One thing to remember is, that powersaving is currently basically ineffective, when wlan is enabled and you aren’t connected to an access point yet, because of the continuous scanning then.

Also there are some more power-management features which I haven’t ported yet from Linux’s iwlwifi. e.g. low-power sending and receiving might improve things a bit more.

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