I'm curious, then. Why do you think ATI chose to ignore VRAM increase and bus width and instead focus solely on bandwidth by tossing GDDR5 on the PCB?
I dont know? How is tossing GDDR5 with a 256 bus focusing on bandwith anymore than GDDR3 with a 448 Bit bus? The bandwith is basically identical give or take. The GTX 260 has about 114 gigs of bandwith while the GTX 280 has about 140. I'm not going to get into a cherry picked benchmark war with you. Your completely missing the point. You dont need to justify your 512 meg cards to me.
Its completely irrelevant to what I am saying. If you run out of memory. No amount of bandwith is going to save your performance because texture/AA data is now being passed through the system bus . Where your bandwith is limited by the PCIE clocks. The bandwith provided by the GPUS doesnt help[ in this case because data is being "waited" on by the system bus. This is not something new or different. You either have the memory or you dont. The entire point of the PCIE bus accessing system memory ((And AGP for that matter)) was to allow for framebuffer overflow to utilize system memory. But the cost is high.
Memory utilization in games is going up. Not down.