What about performance? Is there any case where the 8500 is still
superior?

I always and almost exclusively use the 1024x768 resolution, for gaming.

What do you advice me to do?

Thanks a lot,
Andrea

I just recently picked up an ATI 8500 128Mb on Ebay for $60. Graphics are
amazing and it's fast. Get's a 3DMark01 score of 11,700 on my XP box with a
Barton 3200. To get the same speed levels you need to be looking at a 9500
Pro or a 9600XT. Both of these are DX9 cards, while the 8500 is a DX 8.1
card. That's basically the only drawback. Not too many 9500 Pro's or
9600XT's out there for 50-60 bucks though...