Windows 8: Microsoft hibernates the operating system for faster boot-up

This week developers get a chance to try out Windows 8, the latest version of Microsoft's desktop operating system (OS). The product offers a new graphical user interface using tiles rather than the start menu, which is optimised for touch.

Earlier this year Julie Larson-Green, Microsoft's corporate vice-president for the Windows experience wrote that the user interface supports a new style of Javascript and HTML 5.0 apps, which work with or without a keyboard and mouse on a broad range of screen sizes and pixel densities.

Microsoft's goal is to offer the OS on devices ranging from small slates to laptops, desktops, all-in-ones, and classroom-sized displays.

Early indications suggest the boot time will 30%-70% faster than its predecessor. It remains to be seen how much of the operating services will actually be running when the Windows GUI boots up.

Writing on the MSDN blog, Gabe Aul, director of programme management for Windows at Microsoft, noted: "Now here's the key difference for Windows 8: as in Windows 7, we close the user sessions, but instead of closing the kernel session, we hibernate it." In other word, when a user presses shutdown, all of the programs the user runs are shut down, but the operating system hibernates to memory.

"We're effectively saving the system state and memory to a file on disk (hiberfil.sys) and then read back in on resume and restoring contents back to memory. Using this technique with boot gives us a significant advantage for boot times, since reading the hiberfile in and reinitialising drivers is much faster on most systems (30-70% faster on most systems we've tested)."