Is this the same PowerVR responsible for the Kyro & KyroII graphics cards, circa 2000-2002? They used some clever processing to compensate for a lack of processing power. From what I recall, instead of processing all polygons and textures in a scene then layering them on top of each other (obviously obscuring the ones underneath), the card first figured out what would be on top (ie. in view), and only processed that.
Ultimately a lack of hardware T&L let them down, leaving things to NVidia for a few years until ATi got its act together.