Overclocking

From Pandora Wiki
Revision as of 15:13, 19 April 2011 by ABC (talk | contribs) (App-specific Speed Control: cat)
Jump to: navigation, search

The Pandora's CPU can officially run at 600Mhz, but most Pandoras can also run at higher speeds. This can make CPU-intensive programs (such as an N64 emulator) run smoother. If you try a speed that's too high, your Pandora can freeze up. If this occurs, you can force a restart by holding the Pandora button and sliding the power switch to the right. If you still have problems, take out your battery for a minute before turning on your Pandora (this will discharge the backup capacitor that was designed to retain RTC while the battery is being changed [1])


How to Overclock

Notes:

The OMAP core will actually adjust its speed to match the load; you are setting the upper limit. On its own, reducing the clock speed has little impact on battery life.

The operating voltage is specified as an 'opp' in the range 1-5, with 3 being the default.

GUI Tools

The OS comes with the ability to modify the CPU speed from the GUI. Under "System" in the menu, you should find "CPU-Speed". This gives you a slider to set the desired MHz. Since Hot Fix 5, the maximum and minimum values can be set by using a separate tool (previously, it was limited from 14 to 900MHz).

A second tool was introduced in Hot Fix 5 which allows you to set the maximum OPP level, define the minimum/maximum clock speeds, change the way the "CPU-Speed" script warns you, and define a default clock speed. This can be found under "Settings", then "CPU-Settings".

CLI Commands

For anyone who likes using the terminal, here are some examples:

To set OPP5:

echo 5 > /proc/pandora/cpu_opp_max

To set your CPU speed to 800MHz:

echo 800 > /proc/pandora/cpu_mhz_max

Voltage Scaling

At low frequencies, the OMAP can still work with a reduced voltage, and that causes it to drain the battery a little slower. Alternatively, you can increase the voltage and maybe get a higher overclock. This WILL reduce the lifetime of your Pandora. 3 is the default OPP.

If you reduce the CPU speed below specific thresholds, the voltage will automatically adjust downwards. If you set the OPP to 1 whilst still running at the default 500 MHz, your Pandora is very likely to crash. At 4, you may see almost as good an overclock performance as at 5. REMEMBER: OverVolting can potentially halve the life of your Pandora.

App-specific Speed Control

It is possible to auto configure specific applications to increase the CPU speed whilst running. Applications can be configured to prompt with a suggested speed, and you are given the option to select a speed, making the choice persistent if desired. This is done by placing a 'cpuspeed' file in the /pandora/appdata/{pnd_name}/ directory. Delete the file to have the app ask again next time it is run. Some apps, such as PCSX-rearmed, also allows on-the-go overclocking thanks to the sdk.