the differences between Sleep and Hibernate options provided by
Windows Vista shutdown function? Both commands provide a easy and quick
way to leave your computer in existing last state and come back to work
on it at exactly the same state later without waiting too long to system
to restore itself. However, fundamentally there are significant
different between them that allows users to easily choose whether they
should use Sleep or Hibernate.
Sleep is commonly known as Standby in Windows system or S3 in ACPI. In
Sleep mode, the power supply to non-essential and non-critical component
is withheld, and most system operation is shutdown and stopped. All
data in physical memory (RAM module) is still kept in internal memory,
and whole system is place in stand-by mode, which can be woke up and
used almost immediately. In Sleep mode, the power load reduce
considerably, saving a lot of energy. However, the power must not be cut
off, and must be continue to supply to the computer. Once out of power,
the system will have to start again just like a newly boot computer
just started from power off state.
Windows Vista has enhanced sleep mode so that on notebook computer,
sleeping computer will automatically hibernate when battery power level
is low. It also has built-in Hybrid Sleep mode which ensure that system state is preserved when there is power lost.
Hibernate, or S4 in ACPI, meanwhile will save the data in physical
memory to hard disk drive (HDD), and then power off the computer. In
Hibernate mode, a file named hiberfil.sys which has the same file size
as the amount of system memory will be created on the local disk. When
user wants to use the computer again, the computer will boot up and load
back the state at the last hibernation. The advantage of Hibernation
mode is that no power is wasted for maximum saving of power. In
Hibernation dormancy, no electricity is consumed by system. Beside,
restore from Hibernate is generally faster than computer reboot, and is
totally different from fresh start, as users can return to the exact
state of last hibernation with all programs running and documents opened
intact, instead of empty desktop. The disadvantage of Hibernate is that
after a period of time, there may have fragmentation of file. Users
will need to defragment the volume that stores the hibernation file
frequently.