Description of the lag/unresponsiveness:
- Jerky moving, minimising and maximising of windows
- Long waits before application opening (first and subsequent tries)
- Slow GUI actions such as opening tabs in the browser or even the terminal
- Problem is accentuated when using nVidia drivers, although this could be because the system is trying to do more when nVidia drivers are enabled

System description:
- Dell Vostro 1500 laptop
- Core 2 Duo T7100 (1.8Ghz), 2GB RAM, 160GB SATA HDD, Geforce 8600M-GT gfx card

Isolation attempts / diagnosis
- I have installed and tried hard to properly configure Ubuntu x86/amd64, Fedora x86 and Gentoo amd64
- I have tried several nVidia drivers from the following (96.xx, 100.xx, 169.xx, 173.xx)
- Using "nv" or "vesa" drivers produces better 2D performance but of course, there is no 3D. Even with these drivers, Windows with 169.12 nVidia drivers flies in comparison
- Diagnostic commands and logs show nothing wrong (from what I can see), feel free to ask for them though
- The closest thing to something wrong in diagnostic output was an ioctl error and someone suggested I was using the wrong IO scheduler, trying the other ones did not help
- Desktop environment, window managers, decorators or themes do not have any effect and may only accentuate the lag
- CPU frequency scaling governor does not have any effect
- AC power / battery mode does not have any effect
- Ensuring graphics card is "warmed up" does not have any effect
- I have compiled about 30 kernel configurations, none of which have helped
- To compare performance between distinct modes:
- - Windows XP / nvidia drivers (fast 2D/3D, as expected with hardware)
- - Linux / nv/vesa drivers (moderate 2D, no 3D)
- - Linux / nvidia drivers (slow 2D, fast 3D)

Misc
The most accurate description of this problem I have found from someone else can be found here:
http://www.nvnews.net/vbulletin/show...61#post1360861

Conclusion

Due to the advantage of using Linux over Windows for the type of user I am, I have put up with this for months assuming that like WPA2, sound and any other problem, it would be fixed, I just had to be patient. However, this is getting to an unbearable stage, as can be imagined by the fact that I went to the trouble of installing Gentoo.

I would like to express many thanks in advance for any help and pointers to help manage this problem or fix it once and for all.

Could I be sure that a non 8-series graphics card would solve this problem? How sure could I be? Of course, this presents another problem in that it is a laptop and the choices here are limited, probably restricted to other 8-series GPUs...

Did you use 'glxinfo' to check that GLX is running properly?
If the NVidia files weren't installed properly you'll be using the MESA software renderer, which is painful to watch.

On my laptop (Intel 910) I have:
name of display: :0.0
display: :0 screen: 0
direct rendering: No
server glx vendor string: SGI
server glx version string: 1.2
...
OpenGL vendor string: Mesa project: www.mesa3d.org
OpenGL renderer string: Mesa GLX Indirect
OpenGL version string: 1.2 (1.5 Mesa 6.5.1)


Hmm ... maybe that's why I have such awful graphic performance.

Anyway, if the tool tells you that everything is OK, there is absolutely nothing to do but hound NVidia. You may want to plug that card into a WinDuhs machine just to make sure the card isn't defective.
I know the 6800 works beautifully, but no reason to throw away money if it's NVidia's fault the thing isn't working.

Looks fine...

Guess so (and I have tried it in Windows where it performs as expected)

More confirmation that this is 8-series specific

Well, hound NVidia then - follow up on that previous post. They're usually pretty good at fixing reported problems. All in all most people hate the proprietary code though; there have been serious flaws discovered in NVidia's compiled code and reported, but only NVidia can fix it.