Games on the handheld were previously locked at 266MHZ, but Sony's May firmware has unlocked the processor, allowing for clock speeds of 333MHZ.
Shacknews reports than a Sony Computer Entertainment official confirmed with the gaming news site that the May release of updated firmware for the PSP unlocked the handheld's processor speed.
Reported initially as rumors on a fan site, the May 3.50 firmware allows developers to run titles at 333MHZ as opposed to the initial 266MHZ lock, the site reports.
Hackers had already found a way to unlock the full speed at the cost of battery life, but it was unclear whether Sony's official unlock via firmware included any kind of more efficient mechanism to preserve battery life.
The 3.50 firmware also added greater functionality to the handheld, including Remote Play and media functionality.