Although the new Phenom II X6 1090T has two more cores than previous Phenom II X4 processors, the executions cores themselves are largely unchanged; there are just more of them in the X6. However, with this new generation of processors, AMD is introducing a new feature dubbed Turbo CORE.
Since the introduction of their Nehalem microarchitecture, Intel's processors have been outfitted with a feature called Turbo Boost that in essence overclocked one or more of the processor's cores under certain workload conditions, power and thermals permitting. Turbo Boost afforded the processors the ability to enhance the performance of lightly-threaded workloads by increasing the performance of active cores, while inactive cores remained idle. AMD's new Turbo CORE technology functions in a similar way.
AMD's Turbo CORE technology automatically increases the frequency of three active CPU cores by up to 500MHz, without the need for any special software or drivers. The technology will be enabled on Phenom II X6 processors and will work with all AM3-based motherboards after a BIOS update. The Phenom II X6 1090T we tested has a peak Turbo CORE frequency of 3.6GHz, while the 1055T which is arriving today maxes out at 3.3GHz.
Turbo CORE technology works by putting three cores into a boost-enabled P-state when power consumption is below the processor's rated TDP. Being in the boost-enabled P-state doesn't necessarily mean the three cores are overclocked by 500MHz immediately, but rather that they are ready to have their frequencies increased based on the processing workload. When Turbo CORE is active, Cool 'n' Quiet still functions, so each core could be operating at anywhere up to that maximum clock, but is not necessarily at the absolute maximum. And the individual cores don't necessarily have to be operating at the same frequency either. Essentially, when three or more of a Phenom II X6's six cores are at low or no utilization, the processor determines that it is in a boost-eligible state, and the active cores are put into a Turbo-enabled state to increase performance. According to AMD, the active cores must be in a software P0 state for transition to boost and the processors will fully utilize available TDP budget to maximize performance, while remaining within electrical limits.