Local Aussie blogger, Robin, recalls a PSP technical presentation at the GDC by SCEA's manager of developer relations, Mark DeLoura, called "PSP Advanced Software Overview".
DeLoura reveals that the PSP's CPU and bus clockspeeds are configured by software, with the CPU being locked at 222 MHz. PSP?s specs released last year claimed a top speed of 333 MHz.
It is believed that limiting the PSP in this way will help maintain battery life until new longer lasting batteries are in the market. You could expect the PSP running at a 50% greater capacity in the future!
Some more info here..
http://www.kotaku.com/gaming/psp/gran-turismos-ramped-up-psp-040247.php