As the PC release date of GTA:IV grows ever closer and as promised by Kikizo, IGN have been exposed to a recent demo of the game down in San Francisco. Here's a little bit of what they discovered:

Even with all the graphics options cranked and the resolution set at a ridiculous 2560 x 1600 the game still ran well as we sped through the city and blew up as many things as possible. We checked out the specs on the rig and it turns out there was some pretty powerful hardware in there: a Core 2 Extreme X9650 CPU, GeForce GTX 280 graphics card, and 3 GB of RAM. At this setting, the game definitely looked better than the console versions, particularly with regards to the extended draw distance and less pop-up, though that shouldn't be all that surprising.

More info on the demo can be found here: Link