Power usage HP DL 180 G5

[Wilbert Snijders]

Our DL 180 G5 has an Intel SpeedStep CPU (Woodcrest 5140). SpeedStep is enabled in the BIOS. But none of the CPU frequency scaling nor other ACPI power saving features are accessible from within Linux.

So the server uses > 130 W on idle. How can we access the power saving features?

Have I missed a diagnostic tool or something that is supported on the DL 100 server series?

[Ivan Ferreira]

You should ensure that ACPI is enabled at the kernel, check if you booted the system with the noapic option consultin the /proc/cmdline file.

Also, check that the CPU frequency scaling and ACPI is enabled at your current kernel by running:

egrep -i "CONFIG_CPU_FREQ|CONFIG_ACPI_POWER" /boot/config-$(uname -r)

Double check if your BIOS has ACPI enabled.

Don't forget to assign points is the information is useful.

[Ivan Ferreira]

Verify that your CPU supports frequency scaling:

http://acpi.sourceforge.net/documentation/processor.html

"A note about Intel(R) SpeedStep(TM)

When this file shows "" this does not mean that you do not own a Intel(R) SpeedStep (TM) capable processor, or similar technologies from other CPU vendors. It only means that it cannot be controlled using ACPI. For Intel(R) SpeedStep(TM), Intel(R) continues to withhold information about how to set these processor performance states when no ACPI interface is possible. So no driver for Linux is available yet, even though some preliminary reverse-engineering efforts have begun."

Also, check that the cpuspeed service is running:

chkconfig cpuspeed on
service cpuspeed status

[Wilbert Snijders]

Thanks for the hints, I will check these out..

> You should ensure that ACPI is enabled
> at the kernel, check if you booted the
> system with the noapic option consultin
> the /proc/cmdline file.

Do you mean by this, that noapic (or did you mean noacpi?) should or should NOT be set in the kernel command line? I have none of these additional boot parameters set.