nVidia GeForce GT200 Series Anti-Aliasing Investigation
nVidia’s MSAA
As was mentioned earlier, MSAA debuted in consumer space with the GeForce 3 which offered 2x rotated grid and 4x ordered grid modes. Since then nVidia has improved the technique several times. The GeForce 4 series moved the distribution of samples from the top-left of the pixel to cover the entire pixel’s area, while the GeForce 6 series introduced a rotated grid for the 4x mode.
Starting with the 8000 series, nVidia introduced 8x sparse grid MSAA and briefly took the MSAA crown until ATi’s 2000 series introduced the same thing a few months later.
Here are the sample patterns from a GTX285 (these are identical across the entire 8000, 9000 and GT200 product lines). Note that nVidia’s 8xQ setting is 8xMSAA.
The green dots are shader/texture samples, and in each case there’s only one sampled at the pixel’s center, as is typical with MSAA. The blue dots are geometry samples and you can see two, four and eight arranged in rotated and sparse grids. Both vendors do this because such a placement of samples ensures optimal coverage (maximum effective edge resolution).
I run 2560×1600 with 2 gtx280’s and something very noticable was how much smoother all games run with AA (all in game no need for Nvidia control panel) when I upgraded from Vista 64 to Win 7 64. Games like Crysis and COH at 2560×1600 everything maxed with 8xcsa wouldnt even render a frame with Vista, after upgrade to WIN 7 64, COH and Crysis run 16x NP, (Cryis with low FPS obviously) SLI 285’s and 280’s Win7 is the way to go.
Yes, Windows 7 handles SLI/CF better than Vista.