ITReviewed posted a review on the AMD Phenom II X2 550 Black Edition

The latest Phenom II X2 550 Black Edition is the first dual-core Phenom II chip. And it's great for gaming and multitasking. The 3.1GHz processor performs very much on par with Intel's 3GHz dual-core E8400, but costs 50 or so less. Furthermore, for the reduced price you're getting an unlocked processor to play with. The downside is that power consumption is a tad high for a dual-core processor. On the flipside a complete AMD-based system is much more energy efficient than an Intel-based rig. The Phenom II X2 550 Black Edition is an awesome budget processor for enthusiasts - if only it could roll over the 4GHz barrier! It's not the most powerful at running heavy workloads - that's what quad cores are for - but for general computing duties and gaming it's an outstanding buy.

AMD Phenom II X2 550 Black Edition reviewed