cpu - How do the cores in an AMD Bulldozer module compare to Intel HTT virtual cores and two separate cores, in terms of multitasking performance?

This question is basically an extension of Hyper-Threading and Dual-Core, What's the Difference?

The Bulldozer-based AMD FX processors are marketed as having four, six, or eight cores, but physically consist of two, three, or four modules, each with two cores. It is my understanding that the cores in each module share some silicon, falling in between the virtual cores provided by Intel Hyper-Threading Technology and two physically separate cores. How does this affect the performance of AMD FX cores when used for multitasking or other parallel workloads? What about workloads that depend heavily on floating-point operations, such as Folding@home as well as many games?

Answer

Theoretically the efficiency runs somewhere between having the full extra cores and hyper-threading but Intel CPUs have a higher IPC so the increase is rarely enough for an 8core AMD CPU to beat out an Intel quad core with hyper-threading but obviously it will vary from one workload to another.