I suppose upgrades will depend on what you own now.
The Target system is a 900mhz machine. I dont remember the Vid Card, But it wasnt a high end one either. the Goal is to have it run smoothly on that machine.
This means an older Box should still work, but the frame rates might be a bit low. I believe the eye sees something around 30 frames per minute. So having 40 frames would look the same as having 300.
At CON, I believe AH2 was installed on cheapy E-machine. all onboard stuff, Id guess it was like a 1.5 celeron. It ran smooth as silk.
So If your already running a Gig or better box, I think an upgrade on the system, just for AH2 would be a waste of money. Hitech claimed a Video Card to be a better investment.
I personaly am thinking of upgrading to something around 2 Gig, But it has nothing to do with AH2. My 1.1 box works like a charm as well.