DDR3 is coming end of this year/early next year.
I dont understand of being "sync"...because GCards are like their own computer that is solely dedicated to graphics. They have a processing unit, memory, i/o inputs and outputs, bios...etc. So being sync is not between computer and graphic card, but the stuff on the graphic card. All gcards are in sync with there pc housing them, there are bottlenecks...but that is do to a slower part on your machine.