每pixel频宽=Z read + Z write + Color read +Color write = 16bytes/pixel

MSAAx1: 58.982 Mpixels * 56.497 fps = 3332 Mpixels/sec( 53.317 GB/s)
MSAAx2: 58.982 Mpixels * 55.814 fps = 3292 Mpixels/sec(105.345 GB/s)
MSAAx4: 58.982 Mpixels * 54.895 fps = 3238 Mpixels/sec(207.220 GB/s)

如果是Color compression的硬件的话, 在4X MSAA下的耗费大约是
Z read + Z write ( 8 / 48 ) + Color read +Color write ( 8 ) = 8.16 bytes/pixel
3238 MP/s * 8.16 = 25.9 GB/s ~= RSX频宽。
如果场景复杂度提升, 则RSX的频宽会开始出现问题。
这也是NV为每128 bit BUS配备8个ROP的原因：满足最理想情况的理论值。