Sources close to AMD said the company's six-core Thuban processors have some form of dynamic speed boost technology called "C-state performance boost." Intel has incorporated a similar feature into certain Core i5 and i7 processors called Turbo Boost, which allows an operating system to adjust the clock frequencies of a CPU's cores based on performance requirements and the chip's TDP specifications.
Details are scarce, but X-bit Labs reports that "when single-thread performance is needed most, Thuban processors will automatically disable idle cores and overclock the remaining engines to the maximum possible level that is determined by general thermal design power." However, C-state performance boost is said to be hardware-based and will work with any operating system.
Nothing is official, but such a technology would be handy in a six-core desktop processor that supposedly has a TDP on par with quad-core Phenom II CPUs. Thuban is expected to land in May as the Phenom II X6 1035T, 1055T, and 1075T -- all of which are 45nm-based and should work with existing Socket AM2+ and AM3 motherboards.