Benchmarks looked signficant between 6600 and 6800 models to me from these two links:
Depends on the game... there was significant difference in Chronicles of Riddick and Pacific Fighters, but not much in HL2. Some difference in D3. Guess it all depends on which games you're going to play. Wish they included the 6600GT on the 2004 benchmarks -- they had a much better selection of games.
Ahha -- here we go: http://graphics.tomshardware.com/graphic/20041119/index.html
That has both the 6600GT and 6800. Take a look at that too. Ultimately it's up to you -- just remember that the 6800 is about 30% more than the 6600GT... of course, that's only ~$40, but hey -- that's some nice dinners out or a new game!
Speed and performance?!
Well sure... but my point is that the improvements wll come from the newer parts, not some magic in PCI Express or SATA. Sure, they both boast higher I/O rats than AGP/Parallel ATA, but that's not what's making the difference. A video card on both AGP and PCI-Express performs virtually identically. Ditto for a HD that's identical between SATA and PATA.This comment was edited on Oct 22, 12:09.