After a nasty round of rumors that AMD was going to lock down the hidden cores on their Phenom II X2 and X3 CPUs AMD has come out and said they are not going to do that.
The unlocking of cores on the Phenom II X3 and X2 has become something of a fad with people buying them in the hopes of having a fully working Quad at the end of the day.
To AMD this is nothing serious as they view the unlocking of these cores as benign. Apparently they do not feel it hurts sales of the true quad core Phenom IIs.
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Core unlocking, on the other hand, is seen by AMD as something that's relatively benign, enabled in BIOS through ACC and giving users a shot at adding a bit of performance on the side. Anyone would be "lucky" if they managed to unlock all the cores on, say, a Phenom II X2, said Antal Tungler, Technical PR Manager for AMD in Euroland.
Ther real trick to core unlocking is in BIOS and using AMD Overdrive (AOD) 3.0. With AMD Overdrive you can tweak core performance individually, setting affinities and overclocking individual cores, or downclocking the unlocked ones to get a stable unlock.