04 Aug 2016

System Sleep States: S0, S1, S2, S3, S4 & S5

CEans,

CS engineers over here might be able to throw some light on system sleep states S0 - S1 - S2 - S3 - S4 - S5 and why these states are needed.

I'm quite sure lot of us do not know about these sleep states!
yudi

yudi

Branch Unspecified
10 years ago
The states are represented as follows

S1 - Stand By (Power On Suspend) - no system context is lost

S2 - Stand By - CPU and system cache context is lost


S3 - Stand By (Suspend to Ram) - system memory context is maintained, all other system context is lost


S4 - Hibernate - Platform context is maintained.

States S1, S2, and S3 are all various aspects of the Sleep function. If you are running an incompatible video card, some or all of these states will be unavailable.

gauravtiwari89

gauravtiwari89

Branch Unspecified
10 years ago
S1: the most power-hungry of sleep-modes. All processor caches are flushed, and the CPU(s) stop executing instructions. Power to the CPU and RAM is maintained, Basically old machines are more likely to support S1.

S2: The CPU is powered off, this state is rather less found.

S3:In this state, RAM is still powered, although it is almost the only component that is. Since the state of the operating system and all applications, open documents, etc. lies all in main memory, the users can resume work exactly where they left. The computer is faster to resume than to reboot, secondly if any running applications have information this will not be written to the disk, This state is comparatively more common.

S4: In this state, all content of main memory is saved to non-volatile memory such as a hard drive, preserving the state of the operating system, all applications, open documents etc. That means that after coming back from S4, the user can resume work where it was left off in much the same way as with S3. The difference between S4 and S3, apart from the added time of moving the main memory content to disk and back, is that a power loss of a computer in S3 makes it lose all data in main memory.

S5: Soft Off-- Some components remain powered so the computer can "wake" from input from the keyboard, LAN, or USB device.


Cheers.....
mumbles

mumbles

Branch Unspecified
10 years ago
S0 - System On

S1
S3
S4 } These are the SX States
S5

G3 - No AC power to the system

yudi
The states are represented as follows

S1 - Stand By (Power On Suspend) - no system context is lost

S2 - Stand By - CPU and system cache context is lost


S3 - Stand By (Suspend to Ram) - system memory context is maintained, all other system context is lost


S4 - Hibernate - Platform context is maintained.

States S1, S2, and S3 are all various aspects of the Sleep function. If you are running an incompatible video card, some or all of these states will be unavailable.

Naftali

Naftali

Branch Unspecified
2 years ago
Is the sequence generated by the BIOS?
While checking a malfunctioning motherboard, can I control those states sequence manually?

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