Cpu Frequency Scaling For Integrity Mc990 X Systems - HP Integrity MC990 X User Manual

consumption. For example, theoretically, you can cut power consumption if you clock the processors from
2 GHz down to 1 GHz.

CPU frequency scaling for Integrity MC990 X systems

The procedures that explain how to configure CPU frequency scaling on MC990 X systems depend on
whether your system includes the intel_pstate directory. If your MC990 X system includes the
intel_pstate directory, then CPU frequency scaling is enabled with the Intel P State driver. The path
to the intel_pstate directory on your system is: /sys/device/system/cpu/intel_pstate
After checking your MC990 X system for the presence of this directory, the following settings are available
to you:
• The CPU frequency settings for MC990 X systems that include an intel_pstate directory are:
◦ performance (default)
◦
powersave
• The CPU frequency settings for MC990 X systems that do not include an intel_pstate directory
are:
◦
conservative
◦ ondemand (default)
◦ performance. This setting directs the processors to run at or near their maximum speeds.
◦ powersave. This setting slows down the processors and might be suitable for your site during
periods of low use.
◦
userspace
Configuring the powersave setting on systems with the intel_pstate directory
About this task
By default, the CPU frequency setting on MC990 X servers that include the intel_pstate directory is
performance. During non-peak production times, you might want to configure the powersave setting.
To configure the powersave setting:
Procedure
1. Log in as root to the system you want to configure.
2. Use the cpupower command in one of the following formats:
a. To enable the powersave setting, enter the following command:
# cpupower frequency-set -g powersave
b. To re-enable the performance setting, which is the default, enter the following command:
# cpupower frequency-set -g performance
3. Enter the following command to retrieve the setting that is in effect:
# cpupower frequency-info
Verify that the setting you specified appears in the command output in the current policy field.
4. (Optional) Use a text editor to edit the /etc/init.d/after.local file and add the following line:
cpupower frequency-set -g powersave
The preceding line ensures that after each boot, the system sets the powersave setting.
34 CPU frequency scaling for Integrity MC990 X systems