New tech caches the kernel and device drivers only, allowing much faster boots w/out much storage
Microsoft Corp. (MSFT) has come up with a pretty slick solution for Windows 8, its upcoming operating system, which is set tolaunch in late 2012. The company realized that many Windows 7 customers (45 percent on the laptop, 57 percent on the desktop) prefer to do a full shutdown between each use. But wakeup times from full shutdown in Windows have traditional slow.
A small percentage of people hibernate their machines, which promises faster startup speeds, but requires storage space equivalent to the footprint in memory of your running applications (often 4 GB).
So what Microsoft devised was a hybrid method faster startups — this time only storing information from the system kernel and the device drivers. The result is a much faster boot that still provides the power savings of cold boots and hibernation, but without the large amount of storage (often 4 GB or more) needed to store a complete image of all running programs. Microsoft estimates the average cold boot will be 30 to 70 percent faster using the technology.
Microsoft describes the steps to the shutdown side of this process in a blog post, writing:
- The user initiates a shutdown by selecting “shut down” from the Start menu, or by pressing the power button; or an application initiates shutdown by calling an API such as ExitWindowsEx() or InitiateShutdown().
- Windows broadcasts messages to running applications, giving them a chance to save data and settings. Applications can also request a little extra time to finish what they’re doing.
- Windows closes the user sessions for each logged on user.
- Windows sends messages to services notifying them that a shutdown has begun, and subsequently shuts them down. It shuts down ordered services that have a dependency serially, and the rest in parallel. If a service doesn’t respond, it is shut down forcefully.
- Windows broadcasts messages to devices, signaling them to shut down.
- Windows closes the system session (also known as “session 0”).
- Windows flushes any pending data to the system drive to ensure it is saved completely.
- Windows sends a signal via the ACPI interface to the system to power down the PC.
The hybrid boot system pairs with the Unified Extensible Firmware Interface (UEFI) — Microsoft’s new replacement to the aged BIOS system — for ultra-fast boot times, even from near-full sleeps.
Don’t like the hybrid boot and want to do a traditional cold boot? Microsoft has made this easy enough for power users. They can do a traditional cold boot by typing “shutdown /full” from the command line. This allows drivers installers and other programs that require a complete cold boot to still work properly.