Linked by Thom Holwerda on Mon 7th Jun 2010 09:46 UTC, submitted by dmbkiwi
KDE "The latest in the 4.x series of the KDE Software Compilation is due to be released in early August 2010. With the first beta of this release recently unleashed, I thought I'd download the openSuse packages and see what 4.5 has got in store for us."
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RE[3]: ...I
by Fettarme H-Milch on Tue 8th Jun 2010 09:42 UTC in reply to "RE[2]: ...I"
Fettarme H-Milch
Member since:
2010-02-16

Have you compared the sources of KWin and Compiz to check whether both use the same principles to achieve similar looking effects?
I didn't and I guess you didn't, too.

Here's a play of thought:
Let's say Compiz uses OpenGL 1.3 for its effects and KWin uses OpenGL 2.1.
Both Compiz and KWin could be bug-free, but some driver handles OpenGL 1.3 better than OpenGL 2.1.

Of course, I don't know which is the actual reason for the performance discrepancies, however judging by past experience, drivers are likely to blame.
For NVidia GPUs, drivers older than v180 caused many problems with Qt4 and KWin. It was so bad, I installed a beta of v180 that regularly caused X to crash, but the way better performance weighted more.
Since then (1.5 or 2 or so years ago) Qt4, KWin, and Plasma is a smooth experience for me (GeForce 9200M).

I've read similar stories about the proprietary ATI drivers. I suggest to try recent FOSS ATI drivers that are reported to work well with window managers.

Intel had its fair share of problems as well when the internal driver architecture was changed. It caused performance regressions in all sort of areas.

Reply Parent Score: 4

RE[4]: ...I
by righard on Tue 8th Jun 2010 15:33 in reply to "RE[3]: ...I"
righard Member since:
2007-12-26

If OpenGL 2.1 than causes problems with almost all drivers, be it the drivers fault or not, maybe the Kde team should consider switching to OpenGL 1.3.

Reply Parent Score: 1

RE[5]: ...I
by Fettarme H-Milch on Tue 8th Jun 2010 16:17 in reply to "RE[4]: ...I"
Fettarme H-Milch Member since:
2010-02-16

If OpenGL 2.1 than causes problems with almost all drivers, be it the drivers fault or not, maybe the Kde team should consider switching to OpenGL 1.3.

Please read my comment properly. I didn't say that it was actually OpenGL 2.1 or 1.3.
It was just a play of thought why performance differences could possibly occur.

Additionally, your reasoning is completely wrong. NVidia, ATI, and Intel have billions of dollars. They can easily fix their drivers if they are broken (NVidia's drivers are already fixed -- at least for GForce 9200, btw.)
KDE is merely a community project -- with some corporate sponsors, but much less resources nonetheless.

Edited 2010-06-08 16:18 UTC

Reply Parent Score: 4

RE[4]: ...I
by Hiev on Tue 8th Jun 2010 17:00 in reply to "RE[3]: ...I"
Hiev Member since:
2005-09-27

Im not using ATI's propietary drivers, so that's not the problem, is anyone in the KWin world even investigating these problems?

Reply Parent Score: 2

RE[5]: ...I
by Fettarme H-Milch on Wed 9th Jun 2010 00:37 in reply to "RE[4]: ...I"
Fettarme H-Milch Member since:
2010-02-16

is anyone in the KWin world even investigating these problems?

I don't know, but considering that there's no fund raiser for graphics cards for KWin devs, I don't know how you'd even expect voluntary community workers to investigate this.
AFAIK the last person to be paid on KWin was SUSE's Lubos Lunak who -- while still being involve in KDE -- now does other things for his employer (Novell/SUSE), like the KDE Desktop integration helper app for Firefox.

Community FOSS contributors already do work for free. It would be very rude to expect from them that in addition to their voluntary work, they also buy all sorts of graphics cards to investigate a problem that's likely not even caused by them.

This shows once again why it's the GPU manufacturer's responsibility to do that work. They do the driver programming already. They have all sorts of their own GPU models at hand for free.

So if current drivers did not fix the problem, try different ones: The proprietary ATI drivers (on the Radeon) and Nouveau 3D for NVidia hardware. If one of the drivers does not have the problem and the driver is the only component that has changed, the result is pretty clear: Faulty driver. Report the bug for it.

Then it could also be the fault of Xorg. Try different versions of it: The newest and an older one. Problem only on one version: Report an Xorg bug.

If the performance regression persists through all setups, only then you can be sure it's a KWin bug.

Yeah, it's a lot of testing. But think of it: If you are expecting the voluntary KWin devs to "investigate" this, be aware that the devs have to do all the steps as well -- for all sorts of graphics cards they need to buy themselves.

Btw, if you have -- at least to some degree -- found out the cause for your regressions, try to reproduce it with openSUSE and Fedora and report the bug on the bug trackers of Novell and Red Hat (in addition to the upstream bug tracker). Unlike Canonical or some hobby distributor, Novell and Red Hat have capable developers who may be able to fix it.

Reply Parent Score: 3