Slow 3d with composite on

[Eversor]

Hi!
I've noticed that while composition effects work well, 3D on top of it runs at about 1/3 of the normal performance.
I'm using the regular Composite extension and Kwin as the composite manager.
I still don't know if this is some bug on the nvidia driver or it I'm doing something wrong. Ideas?

[Linuxhippy]

How do you measure "3D performance"?

If you are using glxgears, use something more representative like quake3-timedemo (don't know wether openarena also has timedemos).

lg Clemens

[Thunderbird]

I guess you are indeed talking about a simple app like glxgears. Anyway the performance with composite on is supposed to be less. The idea behind composite is that all windows (including 3d ones) are not rendered directly to the screen but to offscreen memory. It is then the task of the composite manager to draw the desktop using the offscreen windows as 'textures'. This causes less performance.

[Eversor]

Originally Posted by Thunderbird

I guess you are indeed talking about a simple app like glxgears. Anyway the performance with composite on is supposed to be less. The idea behind composite is that all windows (including 3d ones) are not rendered directly to the screen but to offscreen memory. It is then the task of the composite manager to draw the desktop using the offscreen windows as 'textures'. This causes less performance.

Yes, it was with glxgears.
But even fullscreen, like unreal tournament 2004, I get this kind of performance drop.
But with AIGLX, for example, working fine, isn't the performance supposed to be the same?

[mooninite]

Could you post real benchmark numbers? We have nothing to base your claim over. Run the timed demos from UT 2004, Quake 4, or ET: QW.

What video card and driver are you using? What Linux distribution?

This post won't do much good without some more specifics.

[Linuxhippy]

so are you using XGL or AIGLX?
Both have some overhead, but AIGLX will be better with nvidia cards.

lg Clemens

[Eversor]

Originally Posted by mooninite

Could you post real benchmark numbers? We have nothing to base your claim over. Run the timed demos from UT 2004, Quake 4, or ET: QW.

What video card and driver are you using? What Linux distribution?

This post won't do much good without some more specifics.

I can post even screenshots if you want.
But, quickly, it's like this:

glxgears without transparency on: ~10000FPS
" with : ~3500FPS
UT2004 without : ~100FPS
UT2004 with : ~ 35FPS

UT's performance changes a lot, but top FPS with transparency on is like 60 instead of 150FPS and it obviously also reflects on the minimum FPS which is also like 20 instead of 50-60.

The computer is a ASUS P5N-E SLI with core 2 duo E6400 @ 2.66GHz and a 7600GT.
Distribution is gentoo linux with all stable packages.

The performance drop is on the fly, I don't need to restart the X server, if I go to KDE's window properties and turn on Transparency, it starts working and performance drops immediately.
I'm just using the composite extension and Option "AllowGLXWithComposite" "true".

[Eversor]

Ideas please...
No one has any clue if this is a bug in the driver or the software?
best regards.