Xbox 360 has just as IBM recently confirmed a processor with three PowerPC cores which can each handle two hardware threads simultaneously. There have been going rumours about why they have chosen to use three cores, which doesn’t really fit the general picture of multicore systems where you almost always have an even number of cores. According to information from a Xbox 360 enginerr the reason is ATi’s Xenos graphic circuit. The powerful graphic circuit uses 2 cores and its two separate threads to keep the pipeline full. With the right coding this would mean that two cores would be working with keeping the graphic circuit busy while one core would do the rest of the work not related to the graphics.
Considering that no games from the first generation will be multithreaded to any major extent there is still a lot of power that will be left unused.
Source: The Inquirer
