For many months now, hardware enthusiasts have known that it is possile to gain an extra core with a just a little bit of tinkering. With the ACC feature (advanced clock calibration) found in many new motherboards, mnay people have successfully unclocked a second core on cheap single-core AMD Sempron CPUs, and many others have had luck unlocking a fourth core on Phenom II X3 parts.

But that's not all that can be accomplished with a little ACC'ing, though.

A few overclockers have found recent success turning a Athon II X4 620 or 630 CPU into a full-fledged Phenom II X4 just by using ACC. Instead of a core being unlocked, the ACC is capable of activating 6MB of L3 cache turned off on the chip -- this will bring a huge performance increase, as you might well imagine.

It turns of that for now, the Athlon II X4 620/630 are built on a 'Deneb' Phenom II design. This chips have not hit the mainstream market yet and will not for another few weeks. The 2.6GHz X4 620 will be about $100 USD, while the 2.8 GHz X4 630 will be selling for about $125. 

A 2.6GHz quad core for $100? Count us in.

Be aware though: it is expected that AMD will switch over to the less expensive 'Propus' design for the Athlon II X4 620 and 630. Propus doesn't have the 6MB cache at all, so your chances of activating it using the ACC will be really slim indeed. When this switch will occur is anyone's guess right now.