If you're inclined to mess around with the graphics settings for Grand Theft Auto IV on the PC because you think your system can handle more than the auto-configuration suggests, allow me to give you some advice: don't. You're just going to kill your frame rate.

But since I know you're not going to take that advice (I wouldn't take that advice either), check out this helpful post on Voodoo Extreme that explains all the graphics settings, as well as some command line switches that'll let you force settings the game might be reluctant to let you make.