TPU picked up a rumor from Swedish tech site SweClockers that NVIDIA's upcoming GeForce Titan 780 graphics card will have 6GB GDDR5 memory in its default configuration. That's double as much memory as the GeForce GTX 680, although some non-reference models are equipped with 4GB or even 6GB of GDDR5 memory.
It's known from GK110 block diagrams released alongside the Tesla K20X GPU compute accelerator, that the chip features a 384-bit wide memory interface. With 4 Gbit memory chips still eluding the mainstream, it's quite likely that NVIDIA could cram twenty four 2 Gbit chips to total up 6,144 MB, and hence the chips could be spread on either sides of the PCB, and the back-plate could make a comeback on NVIDIA's single-GPU lineup.
There's no word about the performance of the card, but pricing is expeced to be around $899.