You are following a tutorial for Ubuntu 12.04; are you using 12.04?
If you are not using 12.04 then that's why you got those errors.
If you want to use the x updates PPA, the correct install instructions can be found here:
https://launchpad.net/~ubuntu-x-swat/+archive/x-updates
I don't own any Sandy Bridge, but I've heard there are big improvements in 12.10, so if you are using 12.04 you might consider giving 12.10 a test-drive:
http://www.phoronix.com/scan.php?pag..._intel21&num=1
Also 13.04 is coming out real soon.
What I would do personally is to start a new thread with a descriptive title such as "improve Counter-Strike performance on Sandy Bridge" and wait 24 hours to let the good advice pile up, rather than following a bunch of random tutorials (one of the pages you linked to is from 2008!) and making a big mess. If you rely on unofficial tutorials for the wrong Ubuntu release, then you are asking for trouble... better to gather trusted information, understand the problem, make a plan to solve it, and
then start taking actions to fix the problem (copy & pasting terminal commands from trusted sources only). Good luck, now go start that new thread for your Sandy Bridge problem!
Bookmarks