Taken directly from the article ~
"Gran Turismo in 4 times the resolution of Full HD
Polyphony Digital also presented two technological trials for the next generation at this event. Both of the presentations, were founded on the philosophy of "achieving the highest possible quality" held over the years by Gran Turismo.
One of these, was a time trial competition using Sony's newest digital cinema projector, the "SRX-S110". Gran Turismo 5 prologue is already in Full HD resolution at 1920 x 1080 pixels, providing the highest resolution possible in today's TV content. However in this time trial, the Full HD image was increased to twice the resolution both vertically and horizontally (4x the surface area), enabling game play at an ultra high resolution of 3840 x 2160 pixels. This was performed by connecting and synchronizing four Playstation 3's outputting a quarter of the image each at 1920x1080 pixels, but you must remember this demands an extremely high quality image from the source that can withstand the ultra high resolution. It can be said that this demonstration was only made possible, because the source image was Gran Turismo......"
