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KDE4 desktop effects look wonderful, except when you launch a 2D or 3D OpenGL application, then the application will be extremely slow. If you turn off desktop effects, the 2D or 3D OpenGL application will run normally.

I think KDE4 should notice when such an application is running, and temporarily suspend desktop effects until the program is closed, so the performance of the application isn't affected. There is a shortcut (CTRL+ALT+F12 I believe) that suspends desktop effects, but KDE4 should do that as needed without requiring the user to do anything.

On my old laptop, I noticed that KWin disables compositing whenever it becomes very slow. I think this already is implemented, although the threshold may be adjusted accordingly.

sayakb wrote:On my old laptop, I noticed that KWin disables compositing whenever it becomes very slow. I think this already is implemented, although the threshold may be adjusted accordingly.

I've never noticed such behavior, that must have been a coincidence. As far as I know there is no algorithm in KDE4 to determine when and when not to use desktop effects. There may possibly be something that determines when desktop effects aren't supported with certain hardware but that's about it.

+1. It's similar to what I proposed in another idea:
http://forum.kde.org/plasma-powerdevil- ... 39033.html

Compositing is already disabled when a fullscreen program is running.

It would be good if the user can choose which application disable compositing, though - a "Don't allow compositing" checkbox at the app's proprierities, for example.

in 4.3 at least, desktop effects are automatically disabled when they become too slow. i've actually seen this in action a couple times on my laptop.

note, however, that the "running more than one gl app sucks" problem is an x.org driver problem. if those drivers were properly written and the hardware even half way decent, this wouldn't even be an issue.

This is present on 4.2. A method of adjusting it would be great.

I've not noticed slow-down with 3D applications on my Gentoo box with KDE 4.2.1. I've got the latest nVidia driver and nVidia Geforce Go 6600 graphics card.

Though, if I'm running LOTS of 3D applications and perhaps using other resource-intensive programs, it'll complain when KWin effects become too slow and switch them off.

I'd be content if there was a taskbar plasmoid that would automatically toggle desktop effects [when clicked]. It would save searching through system settings everytime I play certain games on Wine or Crossover.

:thumbs_up:

NuclearPeon wrote:I'd be content if there was a taskbar plasmoid that would automatically toggle desktop effects [when clicked]. It would save searching through system settings everytime I play certain games on Wine or Crossover.

:thumbs_up:

I think this is what you want.

I have a slightly different problem, in that OpenGL screensavers do not work at all if Effects are enabled. This is on my laptop with fglrx driver. On my desktop with the open source radeon driver, everything is fine.

Obviously throttling down Effects won't work in this situation, and neither will a manual switch, but it would be nice if there were a "Turn off Desktop Effects" button in the advanced screensaver configuration.

Perhaps instead of turning desktop effects on or off entirely, it would scale them back as things got worse. So it could decrease the quality of the effects, turn off the effects with the worst performance penalties. That way they could keep basic things (like panel translucency and hiding, taskbar thumbnails, present windows, etc) while losing less important effects (desktop cube, snow, shift and cover application switcher, etc).

Why is this thread still open? The effects already auto suspend when things get slow, and you can tun on/of effects from the system settings as needed.

This feature is already present in KDE 4.3, as effects automatically disable themselves for full screen applications ( which I assume includes the screen saver ) and when the system is encountering performance issues. If you are encountering any issues with either of these two, please file bug reports.

Idea marked as implemented.