Most of our readers should be very familiar with AMD's last 90 nm dual core processor. The first Athlon 64 X2 dual core processors became available in June 2005 at 2.0 to 2.6 GHz clock speed for Socket 939 (Manchester core with 2x 512 kB L2 cache or Toledo with 2x 1 MB L2 cache). This was replaced by the Socket AM2 versions (Windsor F2 core with 2x 512 kB or 2x 1 MB L2 cache). Over time, AMD increased energy efficiency and it introduced faster models based on the F3 stepping of Windsor. While a 65-nm version (Brisbane core, 2x 512 kB L2 cache) with much improved energy efficiency was released one year ago, it has not yet reached the maximum 3.2 GHz clock speed of the 90 nm Windsor F3. This is the model we used for this project.

AMD has two versions of the Athlon 64 X2 6000+, both running at 3.0 GHz and delivering exactly the same performance. The difference is that the newer one is rated at an 89 W thermal design power (TDP) while the first model required up to 125 W. Ours is one of the energy-hungry models, which didn't make any difference for this article.

We ran our benchmark suite at 2.2, 2.4, 2.6 and 2.8 GHz using only one processing core.