How do I invoke Sleep (S3) and not Hibernate (S4) in Vista

[johncp]

My Dell Inspiron 1720 laptop runs Vista Home Premium (sigh).

I'd like to be able to put it into sleep (ACPI mode S3 or "sleep" which is invoked instantly) but instead
it always goes into S4 (ACPI mode S4 or "hibernate") taking up to a minute to update hiberfil.sys.
I could invoke S3 on my old Vaio under XP, so why not under Vista.

How can I set up the 1720 for S3, not S4 ?

Background stuff and what I have found :-

1. The Shutdown Menu

includes options, "sleep" and "hiberate".
BOTH options invoke hibernate (RAM copied to hiberfil.sys).

2 The Registry

The Registry contains about 14 references to S4 - eg

"REG_EXPAND_SZ \system32\powerprof.dll, -54, system hibernate sleep state (ACPI defined sleep state S4)"

but no references (that I find) to S3. I haven't messed with these entries as I don't know which to change or how.

3. The BIOS (A04 - I assume a Dell homebrew)

This contains no references to, or possible entries for, S3/S4 - sleep/hibernate.

4. The command line tool POWERCFG

Reports only S1 & S2 are not supported.

POWERCFG -H OFF does NOT disable hibernate, it only disables the functionkey invocation (Fn+F1)

>POWERCFG -DEVICEQUERY S3_SUPPORTED
>POWERCFG -DEVICEQUERY S4_SUPPORTED

These commands produce identical listings EXCEPT that S4_SUPPORTED includes the following line, which is not listed under S3_SUPPORTED

2Microsoft ACPI-Compliant System"

5. The control panel GUI "Power Options"

doesn't appear to contain any useful options

 

[linney]

This is a good background article.

S3 Sleep in Windows XP.
thread779-1469199

Environmental Data Sheet

http://209.85.175.104/search?q=cach...s3+-canon++"Off+Low+Power"&hl=en&ct=clnk&cd=1

Not too much here but you might like to glance at these?

How to disable and re-enable hibernation on a computer that is running Windows Vista

http://support.microsoft.com/kb/920730/en-us#appliesto

How to troubleshoot performance issues with standby, hibernate, and resume in Windows Vista

http://support.microsoft.com/kb/950686/en-us

The Hibernate option is not available in Windows Vista

http://support.microsoft.com/kb/929658/en-us

You cannot put a computer that has more than 4 GB of memory into hibernation in Windows XP, in Windows Server 2003, in Windows Vista, or in Windows Server 2008

http://support.microsoft.com/kb/888575/en-us

 

[johncp]

Thanks, Linney, for the excellently researched help.

My last post was in error stating that powercfg -h doesn't work.
Actually POWERCFG -h OFF does disable hiberfil.sys, (& removes the "hibernate" option from the shutdown menu & deletes the hyberfil file)

I made more checks and find that invoking hibernate takes up to 57 secs of disk accessing, inc. writing out hiberfil.sys and
55 secs to restart windows + previously running apps.

Sleep takes up to 40 secs of disk accessing to shut down. Restart is under 5 secs.

Now I think the disk accessing when invoking sleep (S3) is not because MS doesn't know the difference between
S3 and S4 and is mistakenly writing to hiberfil, but is due to something quite different. My inspiron does conform to ACPI S3 and I am stuck
with 40 secs of unexplained disk accessing when entering sleep. Both disk caching and system restore are disabled.

BTW I don't understand how Dell get the huge figure of 1.77 watts (their environmental data sheet) for S3, their
measurement method must be worst case & include stuff like battery self discharge and a network connected NIC,
powered for wake_on_network purposes. My understanding of S3 was that RAM is put in self refresh, the CPU ticks
over maintaining registers and all peripherals are off. Therefore power consumption should be a few milliamps.
My old Vaio with a nackered battery slept for days. However the ACPI spec (

http://www.acpi.info/spec.htm)

states the CPU is
shut down in S3. How apps continue to run on wake with the CPU registers wiped I don't know.