In case you missed it while we were out at CES, Microsoft has (for real, this time) released a patch for Windows 7 that adjusts the thread scheduling behavior to accommodate AMD’s Bulldozer-based processors. As you may know, the default behavior in Windows without the patch is less than ideal for lightly threaded workloads, and manually scheduling threads to avoid sharing a Bulldozer module can improve performance. Microsoft briefly released a portion of the patch prematurely in December, but now the full and final updates are available.
This blog post at AMD’s website explains how to obtain and install the patch and what performance benefits to expect from it. The post, by AMD Marketing Manager Adam Kozak, claims the performance gains in applications that do see a change "averages out to a 1-2 percent uplift." I expect we’ll see substantially more improvement, up to 10-15%, in select applications, but we haven’t yet had time to test the patch for ourselves.
We are pleased to see Microsoft making this update to a core Windows component outside of the usual update loop, though. Any future CPUs based on AMD’s Bulldozer microarchitecture ought to benefit from this change, and that may matter quite a bit once the Trinity APU touches down later this year.