Raspberry Pi Overclocking

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Raspberry Pi Overclocking Guide

Is your Raspberry Pi just a little bit on the sluggish side? You wished those menu would be a little more fluid? Then it might be time to consider overclocking your Raspberry Pi. Essentially you are attempting to make the processor or ram run a little bit quicker than originally designed.

Raspberry Pi overclocking will vary from Pi to Pi. Depending on how lucky you get, you may get a 50% increase in clock speed or a 0% increase in clock speed. Remember, overclocking is an art! Some people want a quick overclock and bump their arm_freq, core_freq, and gpu_freq a nominal amount. Others will tweak and tweak to squeeze everything they can get out of their Pi. A failed overclock, reaching the upper limits, will cause system instability or an inability to boot.

NOTE: Overclocking your Raspberry Pi will NOT void your warranty. Overvolting your Raspberry Pi WILL void your warranty.

Most Raspberry Pis can will reach an arm_freq between 800-900, a gpu_freq between 300-350, and a sdram_freq between 450-550 without any overvolting. I think core_freq is between 300-400 without overvolting, as the XBian config defaults it to 375MHz.

There are a few clock values that you can adjust for your Raspberry Pi:

  • arm_freq - Sets the frequency of ARM processor. The default value is 700. (MHz)
  • gpu_freq - Simultaneously sets the frequency for: core_freq, h264_freq, isp_freq, and v3d_freq. (MHz)
  • core_freq - Sets the frequency of GPU processor. This will have an impact on ARM performance. The default value is 250. (MHz)
  • h264_freq - Sets the frequency of hardware video block. The default value is 250. (MHz)
  • isp_freq - Sets the frequency of image sensor pipeline block. The default value is 250.(MHz)
  • v3d_freq - Sets the frequency of 3D block. The default value is 250. (MHz)
  • sdram_freq - Sets the frequency of of SDRAM. The default value is 400. (MHz)
Generally speaking, you need to modify a file name “config.txt”. Usually it is located in the /boot directory. However, this may not be true. You may need to check and see where your “config.txt” file is located depending on your distro; you may even need to add one.

NOTE: You can check your arm_freq by executing the following command in terminal:

cat /proc/cpuinfo

NOTE: gpu_freq controls three values simultaneously. If you wish to control these values independent of one another, you’ll need to disable gpu_freq and enable h264_freq, isp_freq, and v3d_freq.

NOTE: There are two ways to deactivate a clock parameter, you can either completely delete the value from your config.txt or place a “#” in front of the parameter you wish to disable. Placing a “#” indicates that the corresponding line of code is a comment and will not be executed.

IE:
Disabled
#arm_freq=700

Enabled
arm_freq=700

Each distro has a different login and location of the “config.txt” file. Please refer to HTPCBuild.com’s Raspbmc Overclocking Guide, Openelec Overclocking Guide, or XBian Overclocking Guide.