tempral antialiasing is somethign that should only be used when your framerates are through the roof (above 70fps). what it does is do different modes of AA in every frame, so if i did 4x temporal AA, than it would be doing 2x in one frame, 6x in another, 4x in another, 6x, and so on..... its really a trick that ATI cards can do to make 2xAA look like 4xAA, 4xAA look more like 6x, and 6xAA to looks more like 8x or 10x AA. its a neat trick, but usually only the X8xx series can get away with it.