Overclocking the Raspberry Pi

Raspberry Pi uses the Broadcom BCM2835 system-on-chip (SoC) processor which was originally developed to be used with applications that involved heavy graphics and multimedia handling. This led to the design of architecture that pairs a relatively weak and outdated CPU with a massively powerful graphics processor.The CPU instruction set is based on an outdated ARM v6  architecture.

Overclocking the Raspberry Pi is quite different from that of the desktop processors, where if you overclock it and crank up the voltage a few notch you can sustain a higher clock rate with increased power consumption.But the problem with Raspberry Pi is that it uses a mobile phone chip and over-volting can significantly lower the overall chip lifetime.

Even though, since launch Raspberry Pi supported over-volting and overclocking by modifying the "config.txt". The Raspberry Pi can be safely overclocked to 1 GHz without voiding the warranty. Over-volting  is not recommended as it will permanently set a fuse in your SoC and void your warranty.

The latest version of the Raspbian operating system has inbuilt overclock method built into it.With the help of cpufreq driver it offers a “turbo mode”, which can dynamically overclock and over-volt the chip without voiding your warranty.To overclock enter "sudo raspi-config"  in Terminal. Select "overclock" and reboot the system. This will enables dynamic overclocking. If your Raspberry Pi gets too hot(85°C) it will automatically drop back down to 700MHz.

In case the Pi fails to boot due to higher clock, hold the shift key to disable the overclock for that boot session. Link for default clock: http://elinux.org/RPi_config.txt#Overclocking_configuration. Also make sure that you have a decent quality power supply capable of handling the extra load due to overclocking.