While GDDR4 is still working on becoming the standard for high-end graphics cards, it looks like GDDR5 is already being sampled. So what is new with GDDR5, well all we have are rumors but a key one is cyclic redundancy checks or CRC. Perhaps this will turn out to be a sort of 'automatic' throttle for self-overclocking cards.
One of the most interesting pieces of speculation is who is getting their hands on early samples:
“GPGPU freaks will be spooging over this one - as, apparently, will Intel engineers. Rumour has it that the first chaps to get their hands on samples with be the Chipzilla bods working on Larrabee “
If this turns out to be accurate, Larrabee could be quite interesting.