The issue is that most CPU-performance tests don't reflect the potential computational power offered by FX, which has up to eight cores, depending on the version. Sure, computationally-wise, preliminary synthetic tests, such as PCMark 7 and Cinebench, reflect real-world computing performance and indicate that the FX lags in comparison with Intel's Core i5. That's what PCWorld's tests showed after running the four-core FX-4100 through the paces.

Why can't the FX' multi-core design crank past Intel's Core i5 in these tests? Most of these tests are largely geared for CPUs with two or fewer cores. Software makers also have yet to bring to market applications that will take advantage of FX multi-core design for multi-threading tasks.

The server equivalent of the FX, code-named "Interlagos"--meant to launch in a few weeks--already takes advantage of the eight cores to a greater extent than the desktop equivalent of the FX does, AMD says.

"AMD FX and Bulldozer CPU technology was optimized for multi-processing and multi-threaded applications," Dina McKinney, corporate vice president, design engineering, for AMD said via email.

The eight cores also benefit from AMD's feature, which automatically boosts the clock speed of different cores when others are not in use above and beyond their normal speeds. When Turbo Core kicks in, the standard clock speed of the FX-8150, the highest-end version of the FX, can speed from 3.6GHz to 3.6GHz.