I currently have a GF4 Ti4200 and I was thinking of an upgrade. (Since my aunt just gave me a new P4 550 and an ASUS P5P800 as a gift.) So I was thinking of getting either a GF 6600(Not the GT version since I can't find one.), a Radeon 9600XT, or a Radeon 9800 Pro with 128MB. I was thinking of the GF6600 but it seems that it has lower core/memory speeds (300/500). So what do you guys think? Also would it go double the speed of my Ti4200 or not?