In actual terms, PCI Express poses no difference from AGP 8x. At the moment, there really is no reason to get a whole new motherboard. The AGP line goes all the way up to the highest of the PCI Express line. Yes, you're right, the main difference between the two is bandwidth. However, remember that applications and programs today cannot take advantage of the agp 8x bandwidth even today. Therefore, you get the same performance between the two. Often times, AGP cards will go faster that PCI express cards due to technical properties such as latency etc.... The only reason to go PCI x16 is if you have tons of money or you want to prep for the future. Even then, I wouldn't do it; I would wait for dual core chip prices to flatline, and then I'd make the upgrade jump. That will make your buck last the longest.