Microsoft has promised much faster boot times in Windows 8 by employing a hybrid set of cold-boot and hibernation-mode processes during shutdown and start-up.
Windows 8 shutdown would break with the traditional practice of closing all user sessions and shutting services and devices in the kernel session.
“This new fast startup mode will yield benefits on almost all systems, whether they have a spinning HDD or a solid state drive (SSD), but for newer systems with fast SSDs it is downright amazing,” Windows boss Steven Sinofsky wrote on the Windows 8 blog.
Like Windows 7, Windows 8 will continue to close user sessions during shutdown, but instead of closing the kernel session it would hibernate it, explained Sinofsky.
Under hibernation, the operating system saves to disk the system state and memory contents to a hibernation file, which is read back when the device is resumed, he added.
“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 percent faster on most systems we’ve tested).”
The other reason behind its faster boot times was Microsoft's addition of a "multi-phase resume capability" that used multiple cores in parallel, which shared the load of reading from the "hiberfile" and decompressing contents.
The fastest complete boot it achieved under test was between 15 and 20 seconds, while the slowest was just above 30 seconds. It did not share details about what the conditions of the test were.
A video demonstration of a cold boot by a Microsoft employee showed an 8 second start time.
Other features to come with Windows 8 include simultaneous sleep and hibernate which allows the user to resume from a hibernated state in the event of a power loss.
Also, if the device required a complete shutdown, there were several manual methods to perform this, said Sinofsky, as well as an option in the user interface to revert to the Windows 7 manner of shutting down.
