Performance Optimizations For KDE's KWin 4.6

[siride]

Are you sure the Lanczos and Blur filters are properly blacklisted for your drivers/Mesa version in KWin? By default they are only blacklisted for Mesa 7.8.1 and 7.8.2 (KDE SC 4.5.1).

How could I tell?

And if there are some problems with not being able to try the OpenGL renderer at all in systemsettings, you might want to change OpenGLIsUnsafe to 'false' in your kwinrc file and restart KWin. This seemed to be some strange left-over of a previous KWin check, as testing with a fresh user gave no problems.

I had some problems too (with Mesa 7.9, xf86-video-ati-6.13.x, xorg-server 1.9.x) and this fixed it for me (both not being able to enable OpenGL at all and horrible performance with some specific effects)

OpenGL does work, it's just a little bit laggy when I have multiple windows open. I still get framerates above 30 FPS when it's being laggy. But there's no reason it can't be smooth.

[sevens]

How could I tell?

The blur effect was visible with me at least on (semi-)transparent plasma panels (and plasma-themed 'tooltips') and a really low FPS (with blur enabled overall performance was ~20FPS, with blur disabled it improved to 58-62FPS). The Lanczos filter made the present windows effect really slow (<20FPS, even with blur disabled).

For me, changing the following in kwinrc (~/.kde/share/config/kwinrc) fixed the blacklisting for these 2 effects/filters:

[Blacklist][Blur]
Advanced Micro Devices=DRI R600:-:7.8.1,DRI R600:-:7.8.2,DRI R600:-:7.9

[Blacklist][Lanczos]
Advanced Micro Devices=DRI R600:-:7.8.1,DRI R600:-:7.8.2,DRI R600:-:7.9

(added ',DRI R600:-:7.9', left the old lines in tact just in case, might switch back to some older Mesa version for testing later on.) The values seem to be based on the 'OpenGL * string' values from glxinfo

OpenGL does work, it's just a little bit laggy when I have multiple windows open. I still get framerates above 30 FPS when it's being laggy. But there's no reason it can't be smooth.

Do you get this low FPS in normal usage or on some effects? I had overall low performance too when I was still using the blur effect, disabling it (either the effect itself or by blacklisting it, doesn't seem to matter much which one you choose) changed this a lot for me. And that's on a R600 (HD3650), Mesa 7.9 and kernel 2.6.35.7. With normal window usage (e.g. just typing some text, KWin not needing to paint any new effects while doing so) I get ~60FPS, and with effects it's 40-60FPS (depending on the effect, on if it's at the start of the effect or in progress, etc).

[siride]

The blur effect was visible with me at least on (semi-)transparent plasma panels (and plasma-themed 'tooltips') and a really low FPS (with blur enabled overall performance was ~20FPS, with blur disabled it improved to 58-62FPS). The Lanczos filter made the present windows effect really slow (<20FPS, even with blur disabled).

For me, changing the following in kwinrc (~/.kde/share/config/kwinrc) fixed the blacklisting for these 2 effects/filters:

[Blacklist][Blur]
Advanced Micro Devices=DRI R600:-:7.8.1,DRI R600:-:7.8.2,DRI R600:-:7.9

[Blacklist][Lanczos]
Advanced Micro Devices=DRI R600:-:7.8.1,DRI R600:-:7.8.2,DRI R600:-:7.9

(added ',DRI R600:-:7.9', left the old lines in tact just in case, might switch back to some older Mesa version for testing later on.) The values seem to be based on the 'OpenGL * string' values from glxinfo


Do you get this low FPS in normal usage or on some effects? I had overall low performance too when I was still using the blur effect, disabling it (either the effect itself or by blacklisting it, doesn't seem to matter much which one you choose) changed this a lot for me. And that's on a R600 (HD3650), Mesa 7.9 and kernel 2.6.35.7. With normal window usage (e.g. just typing some text, KWin not needing to paint any new effects while doing so) I get ~60FPS, and with effects it's 40-60FPS (depending on the effect, on if it's at the start of the effect or in progress, etc).

I disabled the blur effect very early on as it was obviously an issue. It was the Lanczos filter, which I had heard about, that I had no idea how to disable explicitly.

I get low FPS mostly with moving windows around, or with sliding Plasma popups (such as the K menu). Just using, e.g., chrome did not present any noticeable lag.

[sevens]

I disabled the blur effect very early on as it was obviously an issue. It was the Lanczos filter, which I had heard about, that I had no idea how to disable explicitly.

Ok, I hope this helped.

I get low FPS mostly with moving windows around, or with sliding Plasma popups (such as the K menu). Just using, e.g., chrome did not present any noticeable lag.

These things have an impact on the FPS here too, with plasma animations it drops from 60 FPS to ~40FPS for a short while but that's still usable here. Using present windows or cover switch it drops to even 20FPS but that's even barely noticeable (but that's probably mostly due to no fast animations happening in that effect anyway). But that seems pretty sensible to me as KWin has to actually do stuff in those cases

I guess it's a thing that needs to get fixed mostly by better performance of the graphics drivers, as similar 'problems' (relatively low performance) appear on e.g. games, and maybe the KDE/KWin devs could actually do some performance improvements on their own, say, for KDE 4.6?

[monraaf]

Another interesting blog by Martin:

http://blog.martin-graesslin.com/blog/2010/10/kwin-at-uds/

Hopefully Canonical will put some manpower behind driver development...

LOL! If they do that I will eat my shoes.

[Ds342]

"According to Martin, there are great improvements for effects that transform a single window, since these KWin effects no longer cause the entire display to be repainted."

fixed

This large performance improvement applies to effects like Wobbly windows, the plasma "slide" animation and the "Present Windows" effect.