Quote:Are you sure? I think you're talking about how 4gb 680's were getting bottlenecked by the memory bandwidth when using over 2gb of RAM. The 770 has a lot more memory bandwidth, so I'm not sure if this is still true. 224 GB/s vs 192.2GB/s.
I'm going to take a wild guess and simplify how GPUs work, but assuming that a GPU has to read the entirety of the VRAM every frame, I think the 770 will scale better with 4GB.
On the 680, 192.2/60 = 3.20 GB 60x a second, which matches up with benchmarking done on [H]ardForum.
On the 770, 224/60 = 3.73.
Assuming this is right, the 680 is unable to perform 60fps at 3.2 GB usage, and the 770 cannot perform 60fps at 3.7GB usage, only 270mb away from 4GB. On top of that, I think loaded textures don't have to be loaded every frame, so you could still easily run into a RAM utilization wall before you hit a memory bandwidth limit.
EDIT: Also, you would only need to boost the memory from 1752Mhz to 1877Mhz, a 125Mhz increase, to get bandwidth up to 240GB/s, allowing you to transfer 4GB 60x a second.
EDIT 2: I've found through testing that this calculation and assumption is false. However, I still believe that the 770 is capable of utilizing at least 3.5GB of VRAM, if not more.
Edited by DoctorWorm - 6/26/13 at 10:10pm