Instructions
Turn on the Sony PSP and wait for the device to load into the PSP XMB, which is the operating system.
Press the "Home" button on the PSP. This is located underneath the LCD screen on the left side. The visual shell menu (VSH) will appear.
Select "CPU Clock Game," which changes the clock speed of the PSP only during gameplay. Press the "Right" directional button to scroll through the clock speeds.
Press the "Home" button again to verify your selection for the PSP CPU speed and return to the PSP main menu.