I updated to OS 11.1 from OS 11.0 (running KDE 4.xx). After updating, and noticing inconsistencies with monitor standby,etc…, I noticed that 3 different power modules are all running with different settings,
KPowerSave is running (as it was under OS 11.0) with one set of times for power saving functions.
Under Configure Desktop -> Display -> Power Control, is another (and different) set of times for power saving functions (for the same functions as the other two modules).
Under Configure Desktop -> Advanced -> Power Management, is another (and different) set of times for power saving functions (for the same functions as the other two modules). This is the “PowerDevil” module which also runs an underlying service module.
What are the pros and cons to each of these (a comparison)? Why are all three loaded and running by default? I’ve disabled KPowerSave and am trying to determine whether to turn off PowerDevil or the the other module under Display.
I’ve also noticed that I have numerous different ways to alter my power settings. I’m thinking of reducing this to a sinle agent, poehaps KPowersave? Which one I don’t know yet. But I’m also having problems with ‘suspend’. Suspend to disk won’t work at all and comes up with an error message. Suspend to ram sometimes behaves a bit odd. I’d welcome any input into this problem.
Well, OpenSuSE may not take ownership or care for this issue. KPowerSave is obviously a KDE program, and the help documentation for the other modules are KDE as well.
Nevertheless, the PowerDevil module running by itself seemed to do nothing positive except positively use memory. So I stopped and disabled the PowerDevil service module.
KPowerSave only seemed to be intermittently consistent, and I’ve given up (for now) Linux distros’ properly implementing suspend to disk and RAM, so I saw no need to have it running in memory just to suspend the monitor (which I think eats up the most power on my system).
So I’ve defaulted to utilizing just the screen power management under “Display”, and it seems to work perfectly.
I’ve wondered about this myself too… As far as I know, PowerDevil is the power manager for KDE4 and KPowerSave was for KDE3. In practice, however, KPowerSave was used at least by openSUSE in KDE4 while PowerDevil was still in development…
Anyways, this still leaves the display power management in two places as you mentioned. I tried with different settings and it seems that the timings in the “Display” section are the decisive ones and the timings in PowerDevil do nothing. This is using KDE 4.2 RC1 from the build service.
Additionally, one thing I came across with was that if I have screensaver starting before the screen is supposed to go into power saving, it seems that the screen won’t go to power saving state… Anyone else seeing this?