The first Powerwall display was installed at the University of Minnesota in 1994. It was made of four rear-projection displays, providing a resolution of 7.8 million pixels (3200x2400 pixels). Increases in graphic display power, combined with decreases in hardware costs, means that less hardware is required to drive such displays. In 2006, a 50–60 mega-pixel Powerwall display required a cluster of seven machines to drive it, in 2012 the same display could be driven by a single machine with three graphics cards, and in 2015 it could be driven by a single graphics card alone. Rather than seeing a decrease in the use of PC clusters as a result of this, we are instead seeing cluster-driven Powerwall displays with even higher resolutions. Currently, the highest resolution display in the world is the Reality Deck, running at 1.5 billion pixels, powered by a cluster of 18 nodes.