Today Windows updater may have brought "Bulldozer" users a little surprise. A hotfix that increases the AMD flagship processors performance. As this "hotfix" is bleeding edge news any benchmarks have yet to be seen but this confirms Windows 7 was in fact hampering “Bulldozer” from performing at 100% in all prior benches. What percentage it was previously performing at has yet to be determined. Here is a small snippet from the Hotfix release notes.

This article introduces an update that optimizes the performance of AMD Bulldozer CPUs that are used by Windows 7-based or Windows Server 2008 R2-based computers. Currently, the performance of AMD Bulldozer CPUs is slower than expected. This behavior occurs because the threading logic in Windows 7 and in Windows Server 2008 R2 is not optimized to use the Simultaneous Multithreading (SMT) scheduling feature. This feature was introduced in the Bulldozer family of AMD CPUs.

You can download the Hotfix here.