I run a few systems with a mix of ATI, a couple of Nvidia cards and an Intel.
The intel card works beautifully. Good performance in 2d. Plays nicely with other hardware. As others have pointed out though, you'll currently only get these with a motherboard which is a shame.
Older Nvidia cards seem decent depending on the model and circumstances. My laptop's Go 440 works rather nicely, thankyou very much.
Fglrx (the ATI Linux driver) can create some issues with shutdown/hibernate on Linux and occasionally with Broadcom wireless cards. Other than that though the 2d performance (compared to the current hobbled Nvidia 8XXXX series) flies.
A couple of hackish KDE4 tips that helped me:
Replace apps that generate a lot of pixmaps. Use Juk instead of Amarok. Use Konqueror instead of Firefox and Dolphin where you can. Use apt-get in the konsole instead of Adept_Manager.
Killing krunner also seems to help speed on my 8600GT system. Do this by bringing it up with Ctrl+F2, then kill it by pressing Ctrl+Alt+Esc and clicking on it. WARNING: This *will* create some strange glitches until you log in again, most obvious is that it stops various transfer protocols from working, eg move to Trash and all those nice Konqueror shortcuts such as "gg:" for google search.
Keep open windows and tabs to a minimum. (This one hurts me hard. "Hi. My name is Vampie_Donkey... and I am a tabaholic.")
Doing these (with glyphcache settings) seems to create a fairly passable experience on my 8600GT (well if you consider disabling Krunner and various kio slaves passable).
Where I'm Headed:
I'm just hoping that Nvidia will get their act together soon as the fact that ATI:
- Have opened their specs assisting open source drivers
- Are shipping linux drivers on their install CD's
- Are advertising Linux on their promotional materials / packaging
- Have great 2d performance on Linux NOW.
is really making them look like the good option in my book at the moment.
While it's not perfect, my plan is on selling my 8600GT and heading over to ATI land unless I see some decent driver improvements in the next month or two. The only thing that has me pausing from doing it right now is that Nvidia finally acknowledged a problem and a (verbal) willingness to work on it, so I'd still like to do the right thing by them. There's just only so long I'm prepared to wait though.