Hi again EclipseOTO,
AA = Anti-aliasing. It's a form of smoothing edges in games so games look less pixelated and more smooth/true to life.
A good image of how much better an antialiased, 3D image looks can be found here:
http://www.math.ucsd.edu/~sbuss/Cou...er/FinalProjects/chu_tak_sun/antialiasing.JPG
SM3.0 is "Shader Model V3.0"... the X800GTO supports Shader models 1.1, 1.4 and 2.0. There is next to *nothing* out there that uses SM3.0, and the games that do.. really gain little benefit or difference. Age of Empires 3, for example, has *slightly* nicer looking water on SM3.0 cards... but they look just as good on SM2.0 cards and still incredible.
FP16 is a blend mode to enable HDR- which is High Dynamic Range lighting. There are only a couple games out that support this, and of these some require FP16 blends. Half-Life2, Lost Coast- for example, can do HDR on an X800GTO as it uses a different blend mode. Only Oblivion, Far Cry, Splinter Cell and a couple others require FP16 for HDR. Also realize, you have to disable AA (from above) in order to even ENABLE HDR, so you get some brighter colors, but with the jagged look. Newer ATI cards (such as the X1600, X1800 and X1900) allow HDR + AA though, so there isn't any limitation with new ATI cards.
As I said, I have both HDR/FP16 and SM3.0 cards in the house and *still* preferred to add two X800GTO's since these new things really don't amount to much. Oblivion plays GREAT on an X800GTO and there is a "Fake HDR" mod for it to yield nice colors like HDR anyways.. then you can still have nice color and AA smoothing.
And as already mentioned, SM4.0 and DX10 are about to be released, at which point ALL current cards will be obsolete in features. It makes little sense to pay the extra $$ for the smallish improvements in visuals unless you're really, really hardset on HDR.. and don't mind staring at jaggies from lack of AA.
