Random Graphics Lag & UI Lag

[Concha]

I recently installed Mountain Lion as a replacement for Snow Leopard (which worked very well), and everything works amazingly except for the graphics (Nvidia 9500GT), which have been giving me grief...

 

Resolution, sleep, acceleration, etc. are all fine and working well, but the user interface (spaces, mission control/éxpose and such) will randomly chug and jerk when multiple windows are open. Sometimes it's very smooth but, at other times, it's noticeably laggy and icky. Games, like Team Fortress 2, suffer from the same problem... A framerate of 60fps will randomly drop to exactly 30, with a distracting stammering effect. This did not happen in Snow Leopard.

 

I've read about this having to do with AppleGraphicsPowerManagement.kext, but attempting to add in device ids and such has produced no result for me. Is this computer just not good enough for Mountain Lion?

 

Here's its information:

 

Video : Nvidia 9500GT

Memory: 4GB

CPU: 2.33 GHz Quad-Core Intel Xenon

(Seen as MacPro3,1)

 

Please help, this is really annoying me.

[Dr. Hurt]

I have the exact same problem with my GT210

 

There's a problem with the NVDANV50Hal.kext in 10.8.2 that affects all cards using it (ie. older NV cards).

Hopefully it'll be fixed in 10.8.3

 

For the mean time, delete AppleGraphicsPowerManagement.kext which will make things a little better (but not perfect).

[Concha]

I have the exact same problem with my GT210

 

There's a problem with the NVDANV50Hal.kext in 10.8.2 that affects all cards using it (ie. older NV cards).

Hopefully it'll be fixed in 10.8.3

 

For the mean time, delete AppleGraphicsPowerManagement.kext which will make things a little better (but not perfect).

That's pretty disappointing... I hope it gets fixed.

 

I disabled AppleGraphicsPowerManagement.kext, but I can't really notice any difference. If the problem is with NVDANV50Hal.kext, might it be possible to modify it or replace it with the version from Snow Leopard?