Busmastering is an expansion of the PCI-bus developed by INTEL. It allows 2 PCI-bus-peripherals to talk to each other without interrupting the main processor. This allows speedy communication between the 2cards and doesn't slow the main processor down. Speeds go up to 100Mbps in laboratory setups and up to around 60Mbps for real motherboards. This technique is used by the PowerVR to send the pixels that are calculated to the existing graphics card which does the frame buffering and will transfer the image to the monitor. The 60Mbps is more than enough, in general there is 15% left of the 60Mbps. There is NO loss in quality.