mm said:
Reading the url about dumppo.exe, I think it was, they made reference
to the fans not running during Standby, s1 or 2, or 3 or 4.
Mine all run.
Is that bad?
I mean, is the only problem that they use electricity?
Or that they might wear out?
I'm especially thinking about the CPU fan. Is it for sure the CPU
can't overheat during Standby? Even when I don't use air-conditioning
and it might maybe be 90 degrees in the house? I don't remember how
hot it gets.
OTOH, assuming the it never got above 80 in the house, is it a good
idea to fix Standby to make the fans stop?
Thanks.
(Last summer my AC broke, and I have time to fix it before the hot
days, and I plan to, but still I may not.)
http://en.wikipedia.org/wiki/Acpi
* S1: All processor caches are flushed, and the CPU(s) stop executing instructions.
Power to the CPU(s) and RAM is maintained; devices that do not indicate they
must remain on may be powered down.
* S2: CPU powered off
* S3: Commonly referred to as Standby, Sleep, or Suspend to RAM. RAM remains powered
* S4: Hibernation or Suspend to Disk. All content of main memory is saved to non-volatile
memory such as a hard drive, and is powered down.
S5), Soft Off: G2 is almost the same as G3 Mechanical Off, but some components remain
powered so the computer can "wake" from input from the keyboard, clock, modem,
LAN, or USB device.
The fans remain running in S1. S1 basically blanks the monitor (or tries to).
That's about all it does. The PC still has significant power consumption.
If you hear all the fans running, you're in S1.
S3 or S4 should turn off the fans. In S3, your computing session is stored in
system RAM, and the +5VSB from the power supply keeps the RAM powered. In
S4 (hibernate), the computing session is stored on disk, and can survive unplugging
the computer and plugging it in again. So if you have unreliable AC power where
you live, you would choose S4 rather than S3. At the shutdown menu, press the
shift key, and notice one of the options for shutdown changes. That's how
you get to hibernate, with the shift key.
In terms of reliability, I have one motherboard, that fails to restore from S3,
in about one out of three attempts. I don't use S3 with that motherboard, and use
S4 instead. For all the others, S3 works properly, and I have no concerns using
S3 with them.
When I put a computer in S3, startup is relatively quick. Using S4 is
safer, in that the session is saved to disk, but it takes a few seconds
longer to reload RAM contents from the disk file (hiberfile).
The BIOS offers some ACPI S1,S3,S1&S3 options. The OS must have an ACPI HAL
in place, to use the ACPI table values passed by the BIOS, and be able to
do things like suspend to RAM or hibernate. You'll notice, when the computer
starts up the next time, that the BIOS "knows" it is in a particular S state,
as the normal boot sequence doesn't take place. So there must be some
hardware bits set, that tell it what state is involved. I suspect the
OS has knowledge as well - for example, if going from unplugged, to
"hiberfile available", the OS knows it should reload from the hiberfile,
rather than starting a fresh session.
The dumppo program allows observing the choices available, and overriding
mistakes to some extent. But ACPI is complicated, and apparently there
are a fair number of registry entries involved in one way or another.
For example, your Power control panel also exerts some control over
ACPI and how the computer runs (i.e. Processor C states).
Paul
