I can assure you there's a difference, but it depends on the resolution you are playing at. My brother has a 8600GTS 512 and I previously owned a 9800GTX+. the 8600GTS struggles (~24fps) with Crysis on 1280x1024 while the 9800GTX+ gets reasonable frame rates on high on 1920x1080 (First build I hooked up to my 60" hdtv.. it was sweet
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