What do I use to save power when idling with my Intel Core 2 Q8200(quad-core; default clock speeds; Socket 775 LGA) in Debian/Linux?

Hello.

In AMD, I used PowerNow to save power when idling in my old Debian/Linux
box. Yesterday, I upgraded to an Intel Core 2 Q8200 (quad-core; default
clock speeds; Socket 775 LGA) system. What do I use for it? This is
mainly a workstation and acts as a private SSH2 server.

Thank you in advance.
--
"Though your enemy is the size of an ant, look upon him as an elephant."
--Danish
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In message Ant
was claimed to have wrote:

In AMD, I used PowerNow to save power when idling in my old Debian/Linux
box. Yesterday, I upgraded to an Intel Core 2 Q8200 (quad-core; default
clock speeds; Socket 775 LGA) system. What do I use for it? This is
mainly a workstation and acts as a private SSH2 server.

I can't speak to Debian, but most modern OSes have an idle thread that
automatically idles the CPU via the HLT command.

It might be motherboard dependant but if you have SpeedStep enabled in
your BIOS then this should be taken care of automatically in the Intel
world, or at least it seems to be on my boxes.

On 12/21/2010 2:31 PM PT, DevilsPGD typed:

In AMD, I used PowerNow to save power when idling in my old Debian/Linux
box. Yesterday, I upgraded to an Intel Core 2 Q8200 (quad-core; default
clock speeds; Socket 775 LGA) system. What do I use for it? This is
mainly a workstation and acts as a private SSH2 server.

I can't speak to Debian, but most modern OSes have an idle thread that
automatically idles the CPU via the HLT command.

It might be motherboard dependant but if you have SpeedStep enabled in
your BIOS then this should be taken care of automatically in the Intel
world, or at least it seems to be on my boxes.

Hmm, I am not sure where that is in my CMOS. Is there a way to check in
Debian/Linux to see if it is enabled? So SpeedStep is enough? I thought
it can slow down like AMD CPUs does when idling.
--
"This is what metaphor is. It is not saying that an ant is an elephant.
Perhaps; both are alive. No. Metaphor is saying the ant is an elephant.
Now, logically speaking, I know there is a difference. If you put
elephants and ants before me, I believe that every time I will correctly
identify the elephant and the ant. So metaphor must come from a very
different place than that of the logical, intelligent mind. It comes
from a place that is very courageous, willing to step out of our
preconceived ways of seeing things and open so large that it can see the
oneness in an ant and in an elephant." --Natalie Goldberg
/\___/\ Phil./Ant @ http://antfarm.ma.cx (Personal Web Site)
/ /\ /\ \ Ant's Quality Foraged Links: http://aqfl.net
| |o o| |
\ _ / If crediting, then use Ant nickname and AQFL URL/link.
( ) If e-mailing, then axe ANT from its address if needed.
Ant is currently not listening to any songs on this computer.

In message Ant
was claimed to have wrote:

On 12/21/2010 2:31 PM PT, DevilsPGD typed:

In AMD, I used PowerNow to save power when idling in my old Debian/Linux
box. Yesterday, I upgraded to an Intel Core 2 Q8200 (quad-core; default
clock speeds; Socket 775 LGA) system. What do I use for it? This is
mainly a workstation and acts as a private SSH2 server.

I can't speak to Debian, but most modern OSes have an idle thread that
automatically idles the CPU via the HLT command.

It might be motherboard dependant but if you have SpeedStep enabled in
your BIOS then this should be taken care of automatically in the Intel
world, or at least it seems to be on my boxes.

Hmm, I am not sure where that is in my CMOS. Is there a way to check in
Debian/Linux to see if it is enabled? So SpeedStep is enough? I thought
it can slow down like AMD CPUs does when idling.

The HLT command tells the CPU to power down for a cycle (or more? I
forgot, but I'm think it's more than one cycle)

As far as I know SpeedStep doesn't explicitly need OS support but I'm
basically just a Windows guy. I didn't install/configure anything to
explicitly manage the CPU speeds.

I did fire up some software to monitor my CPU speed though to get a
feeling for whether Turbo Boost was kicking in when I hoped it would
(sadly not, despite loading one core it only kicks in occasionally) and
I could see the cores running at lower than their configured speed much
of the time when idle.

It's possible that Windows is doing some background work but to be
honest, I doubt it's doing much more than issuing HLTs.

["Followup-To:" header set to comp.os.linux.setup.]
On 2010-12-22, DevilsPGD wrote:

The HLT command tells the CPU to power down for a cycle (or more? I
forgot, but I'm think it's more than one cycle)

The CPU stops until it receives an interrupt.


--
A bureaucracy's success is determined by its rebels.

On 12/21/2010 2:31 PM PT, DevilsPGD typed:

In AMD, I used PowerNow to save power when idling in my old Debian/Linux
box. Yesterday, I upgraded to an Intel Core 2 Q8200 (quad-core; default
clock speeds; Socket 775 LGA) system. What do I use for it? This is
mainly a workstation and acts as a private SSH2 server.

I can't speak to Debian, but most modern OSes have an idle thread that
automatically idles the CPU via the HLT command.

It might be motherboard dependant but if you have SpeedStep enabled in
your BIOS then this should be taken care of automatically in the Intel
world, or at least it seems to be on my boxes.

I looked for SpeedStep option in my CMOS (latest BIOS too), but I
couldn't find it. So I looked in both downloaded PDFs
(http://download1.msi.com/files/downl...4v1.1_ASIA.zip and
http://download1.msi.com/files/downl...E7514v1.0.zip), they
said "Intel EIST" and it seems to be only for laptops/notebooks for
their batteries and AC power. BIOS shows it already enabled (GV3).
--
"When I was five years old, I saw an insect that had been eaten by ants
and of which nothing remained except the shell. Through the holes in its
anatomy one could see the sky. Every time I wish to attain purity I look
at the sky through flesh." --Salvadore Dali
/\___/\ Phil./Ant @ http://antfarm.ma.cx (Personal Web Site)
/ /\ /\ \ Ant's Quality Foraged Links: http://aqfl.net
| |o o| |
\ _ / If crediting, then use Ant nickname and AQFL URL/link.
( ) If e-mailing, then axe ANT from its address if needed.
Ant is currently not listening to any songs on this computer.