There may be lots of news about the GTX580 - but at the moment, it's nothing but a rumor, and quite possibly a paper launch, whereas AMD have some actual silicon ready to go with AIBs getting Cayman chips right now.

Supposedly, AIBs have got the Cayman's - which come with 6GHz GDDR5, which means the memory clocks will end up somewhere inbetween 5.5 and 6GHz.

There are various other rumors around the web, but within the next 2 - 4 weeks we should know who has been fibbing, and who will eventually get the best launch and get GPU's into customers hands in time for Santa to come to town.