Huge performance problem with r300 and KWin on openSUSE

[pingufunkybeat]

FWIW, KWin runs fine here on a PCI-x 4550, and is usable on a PCI 4350, at least without the issues the OP is describing.

So you don't need a really powerful card, even if yours is overpowered.

[Kano]

@RealNC

Why did you install fglrx? Your card is not supported since 9-3 driver. You should clean your system from all fglrx parts. Also get rid of radeonhd, nobody needs that.

[RealNC]

@RealNC

Why did you install fglrx? Your card is not supported since 9-3 driver. You should clean your system from all fglrx parts. Also get rid of radeonhd, nobody needs that.

I didn't. Those are the default entries in /etc/X11/xorg.conf.d/ (there is no stand-alone xorg.conf file).

Anyway, I disabled desktop effects. No one seems to mind.

[chrisr]

Flash can use GPU, but why bother?

First you need to make sure the flash plugin is even attempting to use the gpu. Last I heard it does not attempt to unless it detects the binary drivers.

I'm using the r300g driver with a RV350 GPU, which apparently supports all of the requested OpenGL extensions, and so I created a file /etc/adobe/mms.cfg containing the following line:

OverrideGPUValidation=1

Then I restarted Firefox. I didn't notice any subsequent drop in CPU usage while watching any flash videos, but I did notice a large drop in video quality. In other words, the video started tearing very, very badly.

So now I've set OverrideGPUValidation to zero, and the videos are tear-free again.

For the record, I am using a 2.6.38.5 kernel; KMS and PageFlipping are on, and SwapbuffersWait is "off".

[Kano]

How about setting SwapBuffersWait to on?

[marek]

You need SwapbuffersWait set to "on" to eliminate tearing. In the current stack, you can have either maximum performance (i.e. SwapbuffersWait set to "off") or tear-free acceleration, but not both. BTW the same applies to Windows as well, although I think there is a per-app vsync control.

[agd5f]

For the record, I am using a 2.6.38.5 kernel; KMS and PageFlipping are on, and SwapbuffersWait is "off".

Turn SwapbuffersWait on.

[chrisr]

Hmmm, I wonder.... ;-)

Turn SwapbuffersWait on.

You think ? But the more interesting question is "Why use GPU 'acceleration' that doesn't actually decrease CPU usage?". Admittedly, I wasn't watching a full-screen video at the time, but the video window size was OK regardless.

Personally, it makes more sense for me not to use GPU acceleration for Flash, and to keep SwapbuffersWait "off" to increase OpenGL performance elsewhere.