AMDZone has posted details about a Windows XP SP2 dual core hot fix that improves on performance in some situations.
If you run Windows XP on a computer that has multiple processors, single-threaded workloads may move across available CPUs. This migration behavior is a natural artifact of how Windows schedules work across available CPU resources. However, if a computer is running with the Adaptive processor throttling policy, this thread migration may cause problems. Check out the full article over here.