for the graphics drivers you'll need to download the linux nvidia driver from nvidia's website. then when thats done, write down the full path to the file. then press <ctrl><alt><F2> (if you get stuck here or need to switch back to the xsession before you exit it press <ctrl><alt><F7>) to move out of x, but you still need to shut it down in order to install the driver. now after you've switched to the new screen by pressing those buttons, type this
sudo /etc/init.d/gdm stop - this ends the x session
sudo sh thefilename.run - after this, simply follow the step by step.
sudo /etc/init.d/gdm start - starts up a new x session
then it should bring you back into the logon screen. if all went well you should see an nvidia splash screen (maybe). voila, your driver should be up-to-date. hope this helps and doesnt end up screwing you up more lol.
in terms of performance, have you updated all the software? this may help - http://www.overclock.net/linux-unix/...tu-7-10-a.html
- theres a section in there for making sure your updates are, well, up to date haha. good luck!