Microsoft has quietly issued a Knowledge Base article that promises greater performance of AMD Bulldozer processors under Windows 7 and Windows Server 2008 R2.
"Currently, the performance of AMD Bulldozer CPUs is slower than expected," the article states, and explains that Windows 7 and Server 2008 R2 do not support AMD's Simultaneous Multithreading (SMT) scheduling feature.
The #2592546 fix solves the problem, according to Microsoft, and boosts the performance of the chip "to the expected performance level". However, as it is a hotfix and not an official patch yet, Microsoft says it may require further testing and only supplies the software upon special request and recommends that it should only be used by those who are "severely affected by this problem".
If that is not the case, the advice is to wait until the next software update is issued. In any case, the hotfix requires an installed Windows 7 Service Pack 1 (SP1) or Windows Server 2008 R2 Service Pack 1 (SP1).
First tests of the patch reveal a mixed bag of results on AMD's FX-8150 processor. At least those benchmarks suggest that some games will see a slight improvement of performance, while others will decline. The strongest gains are apparently seen in PCMark7 (+14.0 percent) as well as ScienceMark (+10.4 percent).