CPU scaling governors and you

What is your CPU being governed by? Should it be governed by it? Why? How?
Here’s an outlook on the various CPU frequency governors, namely conservative, ondemand, powersave, userspace, and performance, that steps up and steps down the CPU:
conservative
Pros:

  • very much alike the ondemand governor
  • gracefully increases the stepping, unlike ondemand which sets it to maximum when there is any load
  • more suitable for battery powered environments

ondemand
Pros:

  • the best of all
  • sets the speed to what is required
  • saves power
  • doesn’t hinder CPU power, as it scales to what is required

powersave
Pros:

  • sets the CPU statically to use the lowest possible frequency supported
  • you save power

Cons:

  • if you use resource hungry software, your machine may start to lag

userspace
Pros:

  • another application can be used to specify the frequency
  • lets you manually specify the frequency your CPU should run on

Cons:

  • mostly useless!
  • external application may set it low, you save power, but less performance
  • external application may set it high, you consume more power

performance
Pros:

  • statically sticks to the highest possible CPU scaling available, regardless of the available ones
  • your system will run as fast as possible

Cons:

  • takes the most power that you CPU is able to consume
  • not very suitable for battery powered environments, or even to save more power your machine consumes

noatime System Boost

Is your system slow? Do you have to wait 6.2 seconds to start Firefox and other heavy applications?

Well, what you need is the “noatime” filesystem mount option! What exactly happens when system files are read? They are written too! The system writes access times to the files causing unnecessary IO traffic between you and your HDD.

To avoid this, you can mount all your partitions with the noatime option. Simply append “,noatime” beside the “defaults” option in the /etc/fstab and your done!

  /dev/sdb2          /          ext3          defaults,noatime          0  1

Make sure there is no space between defaults and noatime, only a comma.

To test this instantly, execute:

mount -o remount /dev/sdb2

Have fun with the new Performance!