I just noticed that the 780 ti has even higher memory transfere speeds that the 780.
On the 780 ti it's 3 GB GDDR5 with a bandwith of 336 GBps. On the 780 it's 3 GB GDDR5 with a bandwith of 288.38 GBps. Does this have anything to do with PCI-E transfer speeds?
well, there's nothing to do with pcie lanes..
as you can see in the screen shoot, 780Ti has faster memory, 1750Mhz, compared to 1052 Mhz GTX780 memory