I am running Kubuntu 8.04
Dell Latitude D531

My question is simple.
Does KDE 4.1 support the suspend function?
I have not been able to find it or any power management settings.

KDE 4.1 is not officially supported by Kubuntu 8.04

try Kubuntu 8.10 and you should found the suspend function. I see it in Kubuntu 8.10.

Some machines do not support suspend, or there is a configuration issue. In that case KDE hides the suspend options from the user.

bcooksley wrote:Some machines do not support suspend, or there is a configuration issue. In that case KDE hides the suspend options from the user.

HAL should report that the machine supports suspend or hibernate.
You can check that by running "lshal|grep suspend". Solid, which used HAL for powermanagement on Linux can be queried using "solid-powermanagement query suspend". If both report that suspend or hibernate is available, it will show up in kickoff and the logout dialog.

In KDE 4.2, we'll be delivering powerdevil, which is a more advanced system dealing with that. It will make it easy to configure your powermanagement option, such as profiles for powersaving and performance, screen brightness options, suspending after idle time or when battery runs out, ...

sebas wrote:In KDE 4.2, we'll be delivering powerdevil, which is a more advanced system dealing with that. It will make it easy to configure your powermanagement option, such as profiles for powersaving and performance, screen brightness options, suspending after idle time or when battery runs out, ...

I am using kde-guidance-power both in Arch and MEPIS / Debian. This already has all the functionality you mention (except profiles for screen power management). Will it be deprecated in favour of power-devil?

There is also a version of Powerdevil that can be installed in KDE 4.1. i use it and it is pretty good, adding functionality i have not had for ages.

XiniX wrote:I am using kde-guidance-power both in Arch and MEPIS / Debian. This already has all the functionality you mention (except profiles for screen power management). Will it be deprecated in favour of power-devil?

Guidance powermanager has a couple of flaws that I wanted to see fixed in KDE4. First, it gets its data by polling. Then it's written in Python which adds 8MB of memory consumption (if you're not using other PyQt/PyKDE apps at the same time, it's shared memory), not necessarily a problem, but I'd rather not have this memory penalty in an always on application. Powermanager also uses DBus directly and not Solid as far as I know, thereby looses some integration with KDE, and potentially some platform independence features.

PowerDevil on the other hand has a nicer design and is quite a bit more powerful. It integrates better with KDE (uses knotify instead of its own popup, has a KCM as config dialogue, uses a kded daemon for background work) and a couple of other niceties (plasma applets instead of systray, no polling but signal-based operation, profiles, disabling compositing, ...). Those were the reasons for me to concentrate my efforts on PowerDevil for KDE4 rather than on powermanager.

So will powermanager be deprecated? First, it has never before been officially included in KDE, so the question is a bit twisted -- both powermanager and powerdevil are 'new' in that sense. Second, as long as HAL and the corresponding DBus interfaces are kept stable, it should just continue to work. Wether it will be actively developed or not, that's not up to me. Jonathan Riddell has done the port to PyKDE4, and powermanager is currently used in Kubuntu. I'm not aware of any changes right there, but it might make sense to concentrate on getting one application to work really well.

Don't take this as ****, I've been one of the authors of powermanager, though I didn't work on the port to PyKDE4. I don't think it's ported to Solid yet (correct me if I'm wrong, I didn't look at that code recently). I've also done most of the work on the Plasma applet for PowerDevil, so I'd say I know both options pretty well. I'm using powerdevil on a Kubuntu machine right now, and it just works.

[edit: some clarifications]

bcooksley wrote:There is also a version of Powerdevil that can be installed in KDE 4.1. i use it and it is pretty good, adding functionality i have not had for ages.

[font=Arial]Is Powerdevil for use only on laptops or can it be enabled on desktop PC's also ? I have a desktop PC with KDE 4.2.1 (openSUSE 11.1), and can't find the options to Suspend / Hibernate in the Shutdown menu.

Else is there a way to enable Hibernate/Suspend support without PowerDevil ?[/font]

I recently upgraded to 9.04. I wanted to give powerdevil a try, since the hal-based power manager wasn't suspending my laptop. I've searched the repository and cannot find it to install. does anyone know how I can download and install power devil?

Powerdevil is shipped as part of KDE 4.2, and does not need to be installed seperately. It does not have a tray icon, but battery information, controls for brightness and quick suspend / hibernate options are available from the battery Plasmoid. Powerdevil can be configured through System Settings > Advanced > Power Management.