Originally Posted by Xion X2
Since when does a minimum framerate not factor into an average?
No, it wouldn't, and here's why.
Frame-buffer and overall memory bandwidth have the same effect and are interrelated. In fact, you could think of memory bandwidth as composed of 3 key components:
1) Frame buffer
2) Bus width
3) VRAM speed
Each of these plays a role in boosting peak memory bandwidth to speed up texture loading/streaming.
The point of the entire exercise of using a large frame buffer is to increase bandwidth, but if a card already has it due to faster VRAM (such as 4870 with GDDR5 instead of GDDR3) then it doesn't need as large a frame buffer. See how the 4870 has just a little higher bandwidth than the 260 does despite the smaller frame buffer:
Since when does framebuffer size effect bandwidth? If I have 512mb of ram on a 256bit bus or 256mb ram on a 256bit bus, the bandwidth would be the same. More ram is always better, when trhe gpu is actually powerful enough to make use of it. The gddr5 is not gonna make up for the 4870's short comings in the ram department. High levels of AA, AF and high resolutions require more ram.