Throughout the development process of Windows 7, Intel and Microsoft have worked together with a common goal – simplify the PC experience, provide better performance and responsiveness whilst providing better energy efficiency. By both companies working directly throughout Windows 7’s development, we have ensured that the Intel platforms meet all the requirements for Windows 7 and together, our products deliver new ways to improve performance, energy efficiency, security and virtualization. Intel and Microsoft’s collaboration on Windows 7 will be beneficial in several ways:

• Working with Intel, Microsoft implemented support in the Windows 7 kernel for Intel multi-core processors with Hyper-threading Technology, enabling better performance. This will help users get the maximum benefit from multi-tasking.  As well, the Windows Scheduler has improved over time to support both muliticore and Hyperthreaded processors.  Working with Intel, Microsoft implemented a new feature called SMT parking which optimizes the Windows 7 scheduler for Intel Hyper-threading Technology enabling better performance on multi-core, and hyper-threaded Intel processors. Intel and Microsoft developed technology that enables Win 7 scheduler to identify physical vs logical cores, and prioritize physical cores first.  The previous OS could distinguish between logical and physical cores but it scheduled them all in a “greedy” fashion, with the assumption that this would provide the best overall throughput.  This works well for some workloads, but harms others because it may pair up two logical processors on the same physical processor (sharing resources) and leave other physical processors completely idle.

• Intel and Microsoft jointly analyzed the boot/shutdown/sleep/resume times on Intel platforms during the development of Windows 7 to identify opportunities to optimize Intel drivers and BIOS as well as Windows 7. Our mutual goal was to provide the most responsive compute experience possible.

• Another key part of the performance and responsiveness was our collaboration to optimize Intel Solid State Drive technology for Windows 7.

• Our graphics and media teams worked closely to ensure Intel integrated graphics solutions were optimized for the new Windows 7 graphics driver model and enable users to playback high-definition audio and video content on all Intel platforms.  The Intel graphics driver works with the WDDM1.1 model in Windows 7 to reduce its memory footprint using a combination of techniques such as reducing the video memory that is reserved for the driver and moving to a more dynamic memory management scheme.

• Many, many other collaborations across networking, storage, graphics, kernel, server, security, media center and more have resulted in Windows 7 and Intel platforms being designed and tested with each other.

Intel introduced new power management features in the Penryn and Nehalem micro-architectures as Microsoft were developing Windows 7.  Intel and Microsoft worked closely on how to take advantage of these new features.  One of the features is Intel® SpeedStep™ Technology, which allows the operating system to ratchet up and down the performance of the processor at the appropriate times so the workload can execute as efficiently as possible.

Another enhancement was deep power down in the Penryn architecture and they improved on this for the Nehalem microarchitecture. This state allows the processor to go into very deep sleep when idle. Microsoft along with Intel looked at the way that Windows 7 operated to see what was keeping the processor awake. It could be timer ticks being delivered by device drivers that were scheduling timers or it could be background activity. As Microsoft identified these things, they looked at ways to minimize that kind of background activity, in order to enable the processors to get into deep sleeps and stay there. Microsoft added API’s and modified the operating system to try to get idle and stay idle. Microsoft has something called tick skipping where Windows 7 doesn’t actually wake up an idle CPU to deliver a timer tick into it (for example to update the time of day). Microsoft offers something called timer coalescing so that drivers and applications that have timers that have the same period of timer tick but were offset by a slight amount align those two periods and service both of them with just one tick and end up waking up the processor once and not multiple times.  Windows 7 really takes advantage of the deep sleep state when it’s available. If you’re not consuming power on the processor you can enable the battery to last longer because you’re not drawing energy from it. This allows PC OEM vendors to build more energy efficient platforms using Windows 7 on Penryn and Nehalem micro-architecture-based processors.

All of these technical collaborative efforts have resulted in a fantastic operating system taking advantage of key technologies within the Intel processor microarchitecture to produce platforms that are performing up to 6 times faster with certain workloads.  Take a look at my blog tomorrow to see more about the performance figures and to see why you should buy a new PC running with the Windows 7 operating system.