Originally Posted by ChrisRay
Which I dont. Most of the disparities seen between the GTX 280/260 can be accounted for the additional pixel pipes and clocks. Bandwith does help a little. But I think you'd be surprised how much FPS bang you get per bandwith verses how much FPS bang you get with higher pixel fillrate. I do to this day believe the GTX 280 has more bandwith than it needs. This is why high core overclocks of the GTX 260 make it so easily caught up with the GTX 280.
The latest games are bounded by the arithmetic power (SPs), but, the old games that need less arithmetic clock cycles per pixel, became bounded by the bandwidth.
Once you have enough arithmetic power, bandwidth is the constraint.
High resolution textures do need a lot of bandwidth (ex: my BR2 patch uses texture compression to save bandwidth), high AF needs to read more texels from the textures, SSAA does not use buffer compression, pixel blending uses a lot of bandwidth (bloom effects), ...
High bandwidth guarantees that your arithmetic power (your SPs) will be feeded with all the data that it needs.
This is a problem for the CPUs with more than 8 cores, so, try to imagine the memory wall in a GPU with thousands of SPs:
Again, the memory bandwidth is like the gold ingots of a gfx card.