Originally Posted by Kaldari
256 bit and 4GB would also be an option. I'd like to see a bench where the VRAM bus made any real-world difference in frame rate. The loads will be slightly faster, but the difference is utterly negligible. Saying that in order to fill the RAM requirements of 100% of games means I have to double the already premium price for a GPU isn't much of an argument.
It makes a fairly significant difference, at least between 256 and 192 bit. The 670 and 660 Ti are identical, except the 660 Ti has the smaller bus and the associated removal of ROPs. In memory bandwidth/ROP heavy titles the difference is around 20%, so just shy of the 25% difference in bandwidth and ROPs. Other games seemed to hover around 12-15%, and bandwidth light games such as Portal 2 suffered no loss in performance.
It's possible the memory interleaving has some effect, but I'm willing to guess it is mostly bandwidth/ROPs.
Originally Posted by tpi2007
Nvidia could technically release a 3 GB GTX 770 (the rumour up to now has it with 4 GB of VRAM, but if the latest rumours about the GTX 780 coming with 3 GB of VRAM are true, then it wouldn't make sense for the GTX 770 to be released with more), couldn't they ? If they can release a 2GB card with a 192-bit memory bus using that techinque of theirs, surely they could release a 3 GB GTX 770 on a 256-bit memory bus ?
It's possible and could happen in 2 ways: 4x lanes with a single 2Gb (256MB) chip each, and then 4x lanes with 2x 2Gb chips. Alternatively, 8x 2Gb + 1Gb. I'd be rather surprised to see this happen though.
An alternative is that Nvidia moves to SK Hynix's 4Gb chips, essentially doubling memory on all cards. These just hit the market Q1 this year, so I'm not seeing this happening any time soon. It does explain how the PS4 went from the rumored 4GB GDDR5 to the now official 8GB GDDR5. Same pinout, double the memory, no PCB change needed.Edited by zinfinion - 5/17/13 at 8:35pm