answered
2019-03-23 17:33:03 +0200
Power saving mode is an old feature inherited all the way from Nokia Maemo devices like N900 i.e. Sailfish OS has kind of supported it under the hood from day zero.
What changed now is that I became officially supported feature: It has a place in the settings UI, it has received testing attention, some quirks/hiccups with triggering etc have been fixed, and it hopefully will become more useful in the future.
Currently the only real effects of PSM getting triggered are:
- Display brightness is toned down
- Background synchronization tasks are skipped
- The indicator icon is shown in status bar
The relevant settings can be manipulated from CLI with mcetool
options:
-p, --set-power-saving-mode=<enabled|disabled>
-T, --set-psm-threshold=<10|20|30|40|50>
-F, --set-forced-psm=<enabled|disabled>
(Note that - despite the instructions above - the threshold can be freely set to 0...100 % range)
EDIT: 2019-03-25
Looks like there is indeed a glitch in how initial default state is configured vs. interpreted by the settings UI.
Initial configuration state is "Threshold = 20%, feature = disabled". The feature is enabled only when the threshold value changes -> as long as user does not change the value / selects 20%, the feature stays disabled.
Remedy: Selecting any other threshold (say 10%) changes the situation to "Threshold = 10%, feature = enabled". After that the feature stays enabled (and also 20% can be selected).
EDIT: 2019-03-28
Fix for the setting glitch exists and should be included in sfos >= 3.0.3.x
It doesn't really help when you change the question to something completely different as all the previous answers now seem to have to connection to the question whatsoever.
The original question was:
ossi1967 ( 2019-03-23 19:21:08 +0200 )editAnyway, what does this battery saving mode do? I would like to know as many mechanisms that were "sold" as battery saving do not work on modern mobile hardware or are actually counterproductive. On modern mobile CPUs emptying RAM, reducing RAM usage cache or reducing clock rates actually increase battery drain instead of reducing it.
Shoppinguin ( 2019-03-24 20:13:56 +0200 )edit@Shoppinguin: Check the answer of spiiroin, please.
jovirkku ( 2019-03-25 12:30:08 +0200 )edit