Check out the results of the Valve survey here
http://www.steampowered.com/status/survey.html
pretty interesting to know the config of HL2 players worldwide. And lemme tell you AMD is not far behind Intel and lots of other comprehensive stuff presented in a simple manner. You can participate in it too. The steam client on your PC (supposing that you have some Valve game) will prompt you to participate in the survey. No form filling no nothing. Just click and Submit your System Information