core i3 で speed step

Intel Core i3 にも SpeedStep が搭載されているので設定
Atom のとき
http://cskimura.blogspot.com/2009/07/speed-step.html
でやっているのでそのまま

acpi_cpufreqモジュールのロードを確認

# lsmod | grep acpi_cpufreq
acpi_cpufreq            5555  0 
processor              29479  5 acpi_cpufreq

cpufreqd のインストールと確認

# apt-get install cpufreqd cpufreq-info
# cpufreq-info
cpufrequtils 006: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0 1 2 3
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 1.20 GHz - 2.93 GHz
  available frequency steps: 2.93 GHz, 2.80 GHz, 2.67 GHz, 2.53 GHz, 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz, 1.60 GHz, 1.47 GHz, 1.33 GHz, 1.20 GHz
  available cpufreq governors: powersave, ondemand, performance
  current policy: frequency should be within 2.93 GHz and 2.93 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 2.93 GHz (asserted by call to hardware).
--snip--

おおー、半分以下まで下がるのかー

で、肝心の設定は使わないときは省エネ、使うときにMaxいけばいいので
こんな感じ

$ cat /etc/cpufreqd.conf
[Profile]
name=Conservative
minfreq=0%
maxfreq=100%
policy=ondemand
[/Profile]

[Rule]
name=AC Rule
ac=on                    # (on/off)
cpu_interval=0-100
#profile=Performance High
profile=Conservative
[/Rule]

何もしてないときは1.2GHzまで下がります

# cpufreq-info
cpufrequtils 006: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0 1 2 3
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 1.20 GHz - 2.93 GHz
  available frequency steps: 2.93 GHz, 2.80 GHz, 2.67 GHz, 2.53 GHz, 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz, 1.60 GHz, 1.47 GHz, 1.33 GHz, 1.20 GHz
  available cpufreq governors: powersave, conservative, userspace, ondemand, performance
  current policy: frequency should be within 1.20 GHz and 2.93 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz (asserted by call to hardware).
  cpufreq stats: 2.93 GHz:0.00%, 2.80 GHz:0.00%, 2.67 GHz:0.00%, 2.53 GHz:0.00%, 2.40 GHz:0.00%, 2.27 GHz:0.00%, 2.13 GHz:0.00%, 2.00 GHz:0.00%, 1.87 GHz:0.00%, 1.73 GHz:0.00%, 1.60 GHz:0.00%, 1.47 GHz:0.00%, 1.33 GHz:0.00%, 1.20 GHz:100.00%  (3)
----snip----

CPUを使い始めると2.93GHzまで上昇すると思われ