Although the DOOM open beta doesn't go live until midnight tonight, you can actually fire up the demo (no servers are running yet though). The first thing that caught our eye was this warning to GeForce owners saying that, on the first launch of the game, the game may stutter badly until you reach the menu. The issue should go away after that but may return if you update your drivers in the future. Also of note, there is no menu for advanced video features. We are not sure why this is, but we thought we would mention it.