The Inquirer reports that GDDR5 supplies could be constrained thanks to financial difficulties at many of the memory manufacturers. They do however believe that Samsung could probably handle all the GDDR5 production. They asked AMD about the situation, and they seemed to not be concerned.

DAAMIT says it currently feeds from all three GDDR5 suppliers, although we've only seen Qimonda kit soldered to their babies. "We have two other suppliers for GDDR5 memory and they are Hynix and Samsung. Today they do supply us with devices and they are qualified on our SKUs. There is no concern from AMD on supply of GDDR5 going forward and we only expect things to improve as GDDR5 penetrates more markets." Said Cap'n Hook at DAAMIT HQ. No worries there then. Nvidia's spokesbunny was a bit more coy about the technology "Qimonda's announcement has no impact on NVIDIA's business. We work with multiple memory suppliers to ensure that we have sufficient supply for all our GPU needs."