In advance of its BUILD conference, scheduled to kick off Sept. 13 in Anaheim, Calif, Microsoft has been dribbling out details of its upcoming Windows 8 operating system, courtesy of the Building Windows 8 blog. Posts so far have seemed designed to emphasize that whatever its user interface might look like, the OS will have a wealth of functionality under the skin.

For example, an Aug. 24 posting showed off tweaks to the dialog boxes related to copying or moving files, an Aug. 29 posting showed off Windows 8's revamped Explorer, and an Aug. 30 posting touted the fact that Windows 8 will allow opening .ISO and .VHD files without the aid of a third-party utility. Most recently, an Aug. 31 posting reiterated that the operating system will offer both a traditional desktop and a Windows Phone-style "Metro" interface.

Now, a Sept. 8 Building Windows 8 post reveals that Windows 8 will boot much faster than Windows 7. This is because the operating system now hibernates the operating system kernel session instead of shutting it down, according to Gabe Aul, a Microsoft program manager.

Windows 8 shown booting in just eight seconds
Source: Microsoft
(click to play)

In a video (above), Emily Wilson (another program manager in Microsoft's Kernel Platform Group) boots a laptop loaded with Windows 8 in just eight seconds. To ensure the device -- which apparently is fitted with SSD (solid state disk) storage -- started from a zero-power state, she inserts the battery before turning on the device.

Windows 7's hibernation feature is an existing way of quickly loading the operating system from a power-off state. But, writes Aul, only 11 percent of laptop users employ it, and only one percent of desktop users do so: "Many people want to turn their PCs on and have it be a 'fresh start' rather than running all of the stuff from their previous session."

So in order to get the best of both worlds, Windows 8 will provide a "new fast startup mode which is a hybrid of traditional cold boot and resuming from hibernate," Aul writes. He explains that a Windows 7 shutdown not only closes all user sessions, but also closes services and devices in the kernel session. Windows 8, on the other hand, will simply hibernate the kernel.

Windows 7 startup (top) vs. Windows 8 startup (bottom)
(Click to enlarge)

According to Aul, booting becomes much faster because resuming the hibernated system session is comparatively less work than doing a full system initialization. Also, he adds, a new "multi-phase resume capability" can use multiple cores to split the work of reading from the hibernation file and decompressing its contents. (For those who still prefer hibernation to cold booting, the former will be faster as well, Microsoft promises.)

Windows 7 startup (light blue bars) vs. Windows 8 startup (dark blue), on a range of test systems
Source: Microsoft
(Click to enlarge)

While Windows 8's fast startup mode won't do a full "plug and play" enumeration of all drivers, it still initializes them, Aul writes. Still, a complete, Windows 7-style shutdown may be desired in order to add or change hardware, and this is available by selecting "restart" instead of "shutdown" from Windows 8's user interface, he adds.

Finally, Aul notes, PCs built using Unified Extensible Firmware Interface (UEFI) are more likely to achieve very fast pre-boot times when compared to those with traditional BIOSes. "This isn't because UEFI is inherently faster, but because UEFI writers starting from scratch are more able to optimize their implementation rather than building upon a BIOS implementation that may be many years old," he explains.

Jonathan Angel can be reached at jonathan.angel@ziffdavisenterprise.com and followed at www.twitter.com/gadgetsense.

---