Athlon MPs vs Hyper-Threaded Xeon

Anandtech has a server article up about the performance difference between the MP and Xeon. What is interesting about this article is the hyper threading. Hyper threading allows one physical cpu to have multiple logical cpus, much like you may have logical drives on one physical hard drive. The thinking is that these logical cpus can get resources faster and increase performance. It does on some of the tests.