AMD denies locking cores

Why would AMD kill the golden 'surprise-core' goose?

Rumours of a microcode update that will lock down cores in AMD's new processors have been thoroughly refuted by the company.

AMD reps have come forward and denied any attempt to lock down clock rates on Phenom II cores, although the company will be putting out a microcode update to correct a Cool'n'Quiet bug that has been reported on just the Athlon II X2 model 250 processor. As Athlon II X2 is a pure dual-core die, there is no chance of 'unlocking' hidden cores as there aren't any hidden in there at all.

The Athlon II X2 does derive from the Phenom II architecture, said AMD, but the company opted to decrease the amount of L3 cache in favour of more L2 cache, lowering the overall die size and making the chip's 65W thermal design power (TDP) possible.

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 Europe.

The 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. That way you can avoid upsetting the thermal design, keeping the "poorer" silicon happily stable at lower clock rates.

So, unlocking is possible, and will continue to be. AMD won't actively seek to block cores, as we're sure AMD wouldn't like to harm its potential sales on this dual-core-made-quad gold mine.