Just clarify this please: Are you planning on upgrading from a 512Mb HD3850?
If yes, then no: The 9600 GSO is the same performance, see the list I posted.
An upgrade would need to be : HD4850/9800GTX/9800GTX+ or GTS250 class of card, if you already have a HD3850 that is.
Also post the rest of your specs as well, including monitor resoloution and PSU details.
I would be surprised if your PSU could not run a 8800, but the point is moot, it's the 320 Mb version, and I would leave it alone as well;)
My concern was about the height of the cooler it might block the slot below it, but since you already had a dual slot on the 3850, I see no problems.
Just remember you must fully uninstall the existing ATI drivers before installing the new 9600.
Now you just need to get out the Plastic and order it (the 9600 GSO I mean).
Nah. i'm sticking with the 9600GSO. i can't find the 4370 anywhere and the 9600GSO graphics are Fantastic, even better the my ATi HD 3850, i've seen a video on you tube with the card playing Crysis Warhead