Fast boot times in Windows 8 OS


Read this article to know more about the fast boot time in Windows 8 operating system. Microsoft made it clear that, Windows 8 will have less boot time when compared to other Windows operating system.

Two days back, Microsoft discussed about Hyper-V in Windows 8 Client operating system in its Building Windows 8 blog. Today, Microsoft explained the booting procedure of Windows 8 operating system.

Technically, boot times represent effective system performance and it is very important thing which is used to describe the performance of a system. As per telemetry data which Microsoft have, 57% of desktop PC users and 45% of laptop users shutdown their systems rather than putting them to sleep. Totally, half of all the computer users shut down their systems, while the remaining put their machines to sleep.

Maximum number of people prefer to shut down their machines to make their system completely off and to make sure that, it shouldn't use power and to preserve battery life. While, Hibernate is one of the good options for this, since it doesn't draw power. As per Microsoft's data, many people want to turn off their PCs on to have a fresh start rather than starting from the previous sessions. Many people use sleep/resume for fast on/off switching, but sleep/resume consumes some power to preserve contents of RAM.

Microsoft, wants to manage all these effectively in Windows 8 operating system. So, they decided to reduce the boot time. They thought about Mobile phones which we are using today, which almost never restarts and which will be always in sleep-like state. The main challenge with Microsoft is to design a way which will able to meet all of the users desires on today's PCs without requiring additional hardware. For these, Microsoft kept three important goals for them. They are:

1) Effectively zero watt power draw when off
2) A fresh session after boot
3) Very fast times between pressing the power button and being able to use the PC.

In Windows 7 operating system, Microsoft made many improvements to boot times, which include parallel initialization of device drivers and trigger-start services. To get better boot performance than Windows 7 operating system, it is clear that they should be more creative. For this, Microsoft found a solution. It is a new fast startup mode which is a "hybrid of traditional cold boot and resuming from hibernate". As per Microsoft, below is the way how normal shut down and normal booting process works in Windows 7 operating system.

Shutdown process in Windows 7 OS


1) 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().

2) 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.

3) Windows closes the user sessions for each logged on user.

4) 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.

5) Windows broadcasts messages to devices, signaling them to shut down.

6) Windows closes the system session (also known as "session 0").

7) Windows flushes any pending data to the system drive to ensure it is saved completely.

8) Windows sends a signal via the ACPI interface to the system to power down the PC.

Normal (Cold) Booting procedure in Windows 7 OS


1) After pressing the power button, the PC's firmware initiates a Power-On Self Test (POST) and loads firmware settings. This pre-boot process ends when a valid system disk is detected.

2) Firmware reads the master boot record (MBR), and then starts Bootmgr.exe. Bootmgr.exe finds and starts the Windows loader (Winload.exe) on the Windows boot partition.

3) Essential drivers required to start the Windows kernel are loaded and the kernel starts to run, loading into memory the system registry hive and additional drivers that are marked as BOOT_START.

4) The kernel passes control to the session manager process (Smss.exe) which initializes the system session, and loads and starts the devices and drivers that are not marked BOOT_START.

5) Winlogon.exe starts, the user logon screen appears, the service control manager starts services, and any Group Policy scripts are run. When the user logs in, Windows creates a session for that user.

6) Explorer.exe starts, the system creates the desktop window manager (DWM) process, which initializes the desktop and displays it.
There are a lot more specific details here, if anyone wants to go deeper: http://msdn.microsoft.com/en-us/windows/hardware/gg463386

7) The key thing to remember though is that in a traditional shutdown, we close all of the user sessions, and in the kernel session we close services and devices to prepare for a complete shutdown.

AS per Microsoft, the main difference between Windows 7 and Windows 8 is "As in Windows 7, we close the user sessions, but instead of closing the kernel session, we hibernate it. Compared to a full hibernate, which includes a lot of memory pages in use by apps, session 0 hibernation data is much smaller, which takes substantially less time to write to disk. If you're not familiar with hibernation, we're effectively saving the system state and memory contents to a file on disk (hiberfil.sys) and then reading that 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 reinitializing drivers is much faster on most systems (30-70% faster on most systems we've tested)".

In the following image, you can see the difference in boot process time in Windows 7 OS and in Windows 8 operating system.

Boot process in Windows 7 & Windows 8

Windows 8 is faster because


1) Resuming the hibernated system session will have less work than doing a full system initialization.

2) Another reason is, Microsoft added a new multi-phase resume capability, which is able to use all of the cores in a multi-core system in parallel.

3) Windows 8 don't do a full "plug and play" enumeration of all drivers on every start up.

So, from the Building Windows 8 blog, we can say following are the new features in Windows 8 operating system. They are

1) An App store in Windows 8 OS
2) Support for USB 3.0 in Windows 8 OS
3) Improved Copy Jobs feature in Windows 8 OS
4) Ribbon interface for Windows Explorer in Windows 8
5) An option to mount ISO files without using any optical drive in Windows 8.
6) Virtual Hard Disk (VHD) file support in Windows 8 OS
7) Metro style desktop with traditional desktop
8) Hyper-V technology in Windows 8 Client operating system


Comments

No responses found. Be the first to comment...


  • Do not include your name, "with regards" etc in the comment. Write detailed comment, relevant to the topic.
  • No HTML formatting and links to other web sites are allowed.
  • This is a strictly moderated site. Absolutely no spam allowed.
  • Name:
    Email:
    -