The Laptop Power States
In windows based PC’s and the laptop has normally six sleeping states from power on to fully functional laptop when the display is on Screen. Power states of laptop is represented by
S0 (Fully functional with data execution )
S1 (CPU stop working but all powers is active)
S2 (This state is not generally found in laptops)
S3 (Only Ram has power and data remain.)
S4 (Data is saved in non-volatile memory like HDD and all run power is off )
S5 (Soft-off all suspend/run powers off )
S0 (working state):
This is a fully functional system in which users do their work.
S1 (power on suspend mode):
In this sleep, state CPU stop executing data from the system. which is usually like to turn off the display, stop display driver. Flush CPU registers ALU section stopped working. After all this
The power of CPU is ON. It takes less time to recover in S0 (working state) and it consumes more power in sleep mode near about 160 watts.
This state no longer used.
S3 (standby mode):
In this state, only memory data and supply is ON for save user data. When a user works, all operations like files of the operating system, docs, all running applications are in main memory so all users work retain recover same, where he left it last time. This state consumes less power from S1 OR S2 modes near about 7-15watts.and takes slightly more time to S0 comparatively S1 and S2.
Note: provide some Laptops and desktops bios provide to change suspend mode switching options from S3 to S1 for fast recovery to S0. but consume more power
This is the state where all data and its working image of ram memory is stored in the hard disk which is a non-volatile memory after saving image system is shut all run system supplies. The system needs to restart to recover in S0 mode.
Note: S4 and S3 both function like the same mode but the difference is recovered time and data secure. If S3 mode loses power it can’t recover user data but S4 save it on HDD so it easy and securely recover if power is lost.
S5(soft off or shut down):
It completes turn off all run powers of laptop and does not save any data like S4 mode.
Although it is off but can wake up through a keyboard, LAN and USB cards for woke up the system.