Let's make sure that you understand what you are asking about...
S1 (Sleep) = Processor is stopped but board is mostly powered. System will return to full-powered S0 state (a.k.a. S1 resume) when a keypress, mouse movement/click or some other registered event occurs.
S3 (Sleep) = System goes to a lowered power state wherein processor is stopped but board is partially powered (memory is powered and thus contents are maintained). System will return to full-powered S0 state (a.k.a. S3 resume) when a keypress, mouse movement/click or some other registered event occurs.
Note: If S1 is even supported, you will have to select, in BIOS Setup, whether Sleep means going into S1 or going into S3.
S4 (Hibernate) = System memory contents are saved to disk buffer and system is powered down (only standby power is being received from power supply). System will resume to full powered S0 state, executing BIOS POST and reloading memory contents (a.k.a. S4 resume), when power button is pressed or, if (in BIOS Setup) Wake on LAN from S4/S5 is set to Power On - Normal Boot and support for WOL is enabled in Windows (NIC configuration), a magic packet appears over the (ethernet) LAN.
S5 (Soft Off/Shutdown) = System in off state (only standby power is being received from power supply). System will transition to fully-power (S0) state, executing BIOS POST and freshly booting O/S, when power button is pressed, if (in BIOS Setup) Wake on LAN from S4/S5 is set to Power On - Normal Boot and support for WOL is enabled in Windows (NIC configuration), a magic packet appears over the (ethernet) LAN or, if (in BIOS Setup) Wake System from S5 is Enabled (checked), the configured date/time is reached.
If, in Windows, you select Sleep, you are going to go into the S1 or S3 state (whichever is selected in BIOS).
If, in Windows, you select Hibernate, you are going into the S4 state.
If, in Windows, you select Shutdown, you are going into the S5 state.
From what you have said, anomaly is system doesn't seem to be powering off in Hibernate (i.e. fans are still spinning). Is this what you mean?
I have selected S3 in the BIOS. In Windows I select Hibernate and expect the system to save memory to disk and then fully shut down. This is what I'm accustomed to with other systems (laptops and desktops). In this case the fans do stop but the power button light strobes as if it is in Standby. Maybe with this motherboard that's what Hibernate looks like??
If it will only resume by pressing power button and you see it say loading from disk, then itvis working properly. As for LED, you *do* want to know you're in S4 and not S5, don't You?
Good answer(s). I guess I do wish to know when it's in S4 vs S5, but on other systems Hibernate didn't distinguish between them (via LED anyway). Even the previous motherboard on this computer didn't (an MSI, not Intel). But I'm OK just knowing that it's OFF as much as it can be in S4.
Thanks for the help!
No problem; that's why I am here. Again, just to be sure, if you can wake your system using your mouse, the system is likely in S3 and not S4.
A note to other people reading this thread: The information I have provided here is specific to 4th generation Intel Desktop Boards. In some later generation board designs - and also in the NUC products - you can configure the BIOS so that it will provide power to USB in S4/S5 and can wake the system from S4/S5 based upon USB activity (i.e. Keyboard and Mouse operations).
Hope this helps (and doesn't confuse due to TMI),
This message was posted on behalf of Intel Corporation
The answers above are accurate regarding your inquiry, and I hope they brought clarification to the hibernate question. From our end that is basically the information available for this; however, if you have more questions please let us know.
Thanks Scott, very helpful inputs.