How Fast Start Up works in Windows 8

One of the interesting feature of Windows 8 is Fast Start-Up. Your computer boot time is like 5-10 seconds only, while with previous versions of Windows (e.g. Windows XP, Windows 7, Windows Vista), it was about 30 seconds for a normal PC.

The reason of this fast boot process is the behavior that how Windows 8 shuts down. You've ever heard of Hibernate in Windows, this is the foundation of Windows 8 Fast Start-Up. In Hibernate process, backup of your RAM data has been saved to PC, which include running services, threads, DLLs being executed, programs running; these all are being processed in your primary memories (Cache or RAM), a Backup of these memories has been saved to your Local Hard Drive, while your PC is being Switched Off in Hibernate Mode. Now when you again start your Computer, after Pre-Boot Processes, that Backup has been restored to RAM and other Primary Memories. Restoring these data back to memory is time saving process then again generating data in Memory (e.g. Starting all services, threads, starting programs)

What actually happens when you shutdown your Windows 8 PC -

• All start-up program is being closed
• All running programs have been closed
• System goes in to Hibernate mode (showing Shutting Down Message) 

What happens when you start your Windows 8 PC -

• Post/Pre Boot Process
• Hiberfile Read
• Driver Initialization
• User Session Initialization

What happens when you start Windows XP/7 PC - 

• Post/Pre Boot Process
• System Initialization (Drivers, Services, DLLs)  
• User Session Initialization

It looks like time taken by Windows 8 should be more as compared to Windows 7 due to one more step, but time taken by System Initialization is relatively ~ 6 X then time taken by Hiberfile Read and Driver Initialization.