Thread Management

Windows has been aware of Hyper-Threading and roughly how best to manage logical CPUs since Windows XP. This feature was built upon in the various Windows XP Service Packs that were released and then again with Windows Vista.

Microsoft has further enhanced these capabilities in Windows 7 to cope with Intel's latest Core i7 and Core i5 CPUs, which also feature Turbo Mode to disable unused cores and increase the core frequency on the remaining cores in lightly threaded applications for increased performance. The aim is, of course, to make sure that applications use the right mix of logical and physical CPU cores to achieve optimum performance.

We wanted to test how effective Windows 7's new thread management is, so we used an Intel Core i7-920 in a Biostar TPower X58 motherboard and 6GB of 1,600MHz Corsair Dominator memory. For basic 3D testing, we opted for an ATI Radeon HD 4870 512MB and 3DMark06, as it can be very sensitive to changes in system set up.

We installed both Vista and 7 on identical Seagate Barracuda 7200.12 hard drives to ensure our results were reliable and applied all of the latest updates for both operating systems. We chose a variety of benchmarks, including Cinebench R10, WPrime and the Custom PC benchmark suite.

Both Cinebench and WPrime are able to fully load all eight threads in our Core i7-920 CPU and should act as control tests across Vista and 7. Meanwhile, our application benchmark suite should give us an idea how well the thread management works in everyday tasks such as photo editing, video encoding and multi-tasking.








Even in our control tests, Windows 7 wasn't the same speed as Vista; in Cinebench it was a touch faster, while in WPrime it was slightly slower. 3DMark06 also saw Windows 7 come out a little above Vista. The differences were small, but Windows 7 appears to behave differently to Windows Vista.

In the Custom PC benchmarks, both the image editing and multi-tasking tests were faster on Windows 7. However, the Handbrake h.264 video encoding test was the opposite, with Vista scoring 2,125 points - slightly ahead of Windows 7's 2,068. Of all the tests, we expected this on to fall in Windows 7's favour, so the result is mystifying. However, Windows 7 is roughly as fast as Vista overall when it comes to number crunching on a Hyper-Threaded CPU, even if it was a little sluggish in the video encoding test.