Cell technology: the punch behind PS3

CPUs usually juggle many tasks at once, devoting a small slice of a second to each. By devoting an SPE to an individual task it gets the full performance of the element assigned to it. This multi-processor approach makes the Cell difficult to program for, but it will ultimately allow developers to write some seriously fast applications when they get the hang of it.

What can you do with it?

The Cell has been designed to be the heart of Sony's PlayStation 3 and when Kutaragi first announced the console (back in 2001), he said that it would herald a "new chapter in computer science."

"Today's videogame graphics look like computer graphics," Kutaragi said. "Our goal [withPS3] is to achieve a film-like graphics quality that won't make viewers conscious of or annoyed by the fact that they are indeed looking at computer graphics."

Consoles usually have traditionally had powerful graphics processors and relatively weak CPUs. But the PS3 has a powerful RSX graphics chip from Nvidia (based on the company's G70 architecture) and the largely untapped potential of the Cell CPU. This will open up all sorts of possibilities for future games.

Take ray tracing, for example. Ray tracing is a technique that simulates the reflective and refractive impact of all light rays in a scene. This can create fabulously realistic graphics and has been used to great effect in films like Shrek and Toy Story.

Unfortunately the technique requires so much computational power it's never been used in games. There are some experimental ray traced titles for the PC, but these run very slowly. The use of the Cell processor in the PS3, and specifically its specialized SPEs, means that ray traced games will become a realistic possibility in the future.

The Cell isn't just designed for games though. It's also targeted at next generation home media devices. With compression technologies like H.264 starting to appear, and HDTV gaining a foothold in the UK, we're going to need all the computational power that Cell will deliver.

H.264 can compress video into smaller file sizes while retaining the same or better quality level. It's an impressive feat, but unfortunately it takes around three times more computing power to do so. If you add in six times more resolution for HDTV, the overall computing power required really begins to mount up.

A Cell will also come in handy here as processing high-resolution images is exactly the sort of thing it's designed for. In fact, one of the first commercial uses of the Cell processor will be in a Toshiba HDTV. Toshiba is a major component supplier so you can also expect Cell processors to start turning up in all sorts of other consumer products.

The Cell chip in the PlayStation 3 is only the beginning.

A version of this article, by Nicholas Blachford, was originally published in Digital Home magazine. Nicholas Blachford's original Cell article is available here.