OpenElec Overclocking Guide

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OpenElec Overclocking Guide

This guide assume that you have Putty on your computer and that you know how to connect to OpenElec via SSH. If you you do not, please refer to HTPCBuild.com Connecting to OpenElec via SSH Guide.

You’ve decided that you want to overclock your OpenElec distro. We’ll need to use Putty to connect to your Raspberry Pi and edit the “config.txt” file.

1. First connect to your OpenElec Raspberry Pi via Putty SSH.

2. By default OpenElec does not have a “config.txt”, so we need to create one. The “config.txt” needs to be placed inside of the /flash directory. By default /flash is read only, so we need to remount the directory as read/write. Start by executing the following command:
mount /flash -o remount,rw

3. Now that we have read/write access to the /flash directory, we need to enter the directory to check for the “config.txt” file. Execute the following command to enter the /flash directory:

cd /flash

The terminal will indicate that you are inside the /flash directory.

4. Next we need to view the contents of the /flash directory. We can use the “ls” command to list the contents of the /flash directory, execute the following command:

ls

The terminal will echo back the contents of the /flash directory.

NOTE: If you haven’t already added a “config.txt” file you probably won’t have one here. This terminal is echoing that there is a “config.txt”, which I have previously added.

6. Now we can open up the “config.txt” file. Here we will adjust different clock parameters or add parameters if needed. To open the “config.txt” file execut the following command:

vi config.txt

NOTE: If you do not have a “config.txt” file, ‘vi’ will automatically create a text file name “config.txt”.

7. A text editor will launch and display the contents of the file “config.txt”. More than likely, the “config.txt” will be blank.

8. Before we move forward, you’ll need a quick crash course in how to use the ‘vi’ text editor in OpenElec.

  • When you first open ‘vi’, editor will be in “Command” mode. Command mode allows you to save, exit, etc.
  • To begin editing the file you must enter either “Append” or “Insert” mode. Hitting the ‘a’ key will put the editor into “Append” editing mode. Hitting the ‘i’ key will put the editor into “Insert” mode. If you do not enter “Append” or “Insert” mode, you will NOT be able to edit the file.
  • Once you are done editing, you need to enter “Command” mode to save the file. Hit the “Esc” key a few times, and you should hear the terminal beep. The beep confirms you have entered “Command” mode.
  • To save – hold “Shift” + “:” simultaneously and type “w!”. (Must be in “Command” mode)
  • To quit – hold “Shift” + “:” simultaneously and type “q!”. (Must be in “Command” Mode)

9. Here comes the fun part! Here we can enter parameters we wish to add to the “config.txt” or we can adjust parameters already in it. 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)

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_freqisp_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.

10. To begin editing the file, hit the letter “a” to put ‘vi’ into “Append” mode. We can see that OpenElec by default has no overclocking parameters. More than likely, this is because the distro does not release with a “config.txt” file. You can add the arm_freq parameter to set an overclock on the Raspberry Pi. Changing the value of arm_freq will set a new freq on the next boot. Here the value is set to 800, which will overclock the OpenElec Raspberry Pi to 800MHz on its next reboot.

11. To add another parameter that is not in the “config.txt” file simply enter it in a new line. Here the parameter gpu_freq as been added and set to 300. This bumps the stock value from 250 to 300.

NOTE: The parameter gpu_freq simultaneously sets the frequency for: core_freq, h264_freq, isp_freq, and v3d_freq.

12. When you’ve feel satisfied with your additions and changes, hit the “Esc” key a few time. The terminal will beep at you, this indicates the ‘vi’ editor is now back in “Command” mode. Hold “Shit” + “:” simultaneously to bring up the command line in ‘vi’.

13. Now type the save command, “w!” and hit enter. ‘vi’ will save the file.

14. Now to quit, type “q!” and hit enter.

14. You should now be back in the terminal.

15. Now reboot your Raspberry Pi, and the new settings will take effect! You can reboot your OpenElec Raspberry Pi you can execute the following command:

reboot

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

cat /proc/cpuinfo

That’s it, you’ve overclocked your OpenElec Raspberry Pi. Please make sure to take care when overclocking your Raspberry Pi. Make changes slowly and in small increments. By making subtle changes and testing your Pi you will be able to notice as the system becomes more and more unstable. Look for signs such as random an inability to boot, random freezing, random errors. If you encounter these, SSH into your Pi and back down on the settings. Another option when running into overclocking instability is overvolting. If you wish to experiment with overvolting an OpenElec Raspberry Pi, please refer to HTPCBuild.com’s OpenElec Overvolting Guide.