I am on the last level of Doom 3 with my 3 years old computer.It runs perfect at 640x480 resolution with MEDIUM quality setting selected. The shadow was disabled in order to ease a little on my CPU, everything else is ON. Disabling shadows will give you over a 33% jump in your frame rate.By the way I have the following system: AMD Duron 900 Mhz, Windows 2000, 655 RAM, Sound Blaster Live, ATI Radeon 9200 SE (128 mb), WD 80 GB hard drive (7200, 8M)...nothing to be proud of.I was very surprised that I could increase my settings to MEDIUM quality even though my system doesn't meet the min. requirements of 1.5 Ghz for the CPU. My sound card is 3 years old too.As of today, Doom 3 has the best graphics. In terms of game play - Call of Duty is still #1 for me.