To the surprise of many, last week, Microsoft rolled out a patch (KB2592546) for Windows that it claimed would improve performance of systems running AMD processors based on the "Bulldozer" architecture. The patch works by making the OS aware of the way Bulldozer cores are structured, so it could effectively make use of the parallelism at its disposal. Sadly, a couple of days later, it pulled that patch. Meanwhile, SweClockers got enough time to do a "before and after" performance test of the AMD FX-8150 processor, using this patch.
The results of SweClockers' tests are tabled below. "tidigare" is before, "nytt" is after, and "skillnad" is change. The reviewer put the chip through a wide range of tests, including synthetic CPU-intensive tests (both single and multi-threaded), and real-world gaming performance tests. The results are less than impressive. Perhaps, that's why the patch was redacted.