At a Game Developers Conference session, Sony has moved to dispel the myth that its Next Generation Portable could rival PS3 for processor performance.

David Coombes, a platform research manager for Sony Computer Entertainment America, explained that although the NGP is equipped with a high-performance quad-core CPU theoretically capable of 2GHz, the clock speeds will have to be dialled down in order to preserve the PSP successor's battery life and prevent it from running too hot.

"Some people in the press have said wow, this thing... could be as powerful as PS3. Well, it's not going to run at 2GHz because the battery would last five minutes," he said. "And it would probably set fire to your pants."

In his engineering-themed tour of the NGP's features, Coombes shed some extra light on the handheld's specifications and performance.

He mentioned that the game cards - the solid state physical media on which NGP games will be available in shops - would come in 2GB and 4GB sizes.

NGP games will therefore have a maximum size of 4GB. He compared this to the 9GB size of a typical PS3 game on Blu-ray, or the 10MB size of an average mobile phone game.

Coombes couldn't reveal how much memory NGP will have, but stressed that it was more than enough. "I can't talk about actual numbers, but compared to PSP we have a lot of memory... we're closer to PS3 than PSP in terms of memory size."

NGP will come in two versions: one with wi-fi, and one equipped with both wi-fi and 3G network connectivity. Coombes explained that only the wi-fi plus 3G version would also be equipped with GPS sensors. However, "wi-fi only can still do quite accurate positioning" thanks to Skyhook, a positioning service that works out your location by cross-referencing the wireless hotspots in range with a worldwide databse. "In urban areas, it's more accurate than GPS," he said.

Location-based features would include "treasure hunts" for virtual items in the real world, Coombes said, although these won't be implemented until after launch.

He revealed that NGP's front touch screen and rear touch pad could detect how hard players were pressing on them. Rather than using pressure sensors, this "analogue strength reading" would be achieved by detecting how large a surface area of the player's fingertips were pressed against the screen.

Speaking of the device's beautiful 5-inch screen, Coombes boasted that with its 960x544 resolution and anti-aliasing turned on - 4xMSAA, Digital Foundry fans - "you really can't see the pixels on the screen, which is pretty nice."

Also at the panel, Tsutomu Horikawa, a director from Sony Computer Entertainment International's software solution development department in Tokyo, performed an augmented reality demonstration in which the NGP visualised a giant dinosaur - the T-rex famous from the original PlayStation's first graphics demo - in the aisle of the lecture theatre.

He stepped down from the stage, and craned upwards with the NGP in his hands to view the dinosaur towering above him.

NGP is due to make its first apperance before the end of this year. Check out our NGP gamepage for more infor.