IBM's SuperMuc has had a good week. Not only has the three petaflop machine been listed as Europe's fastest supercomputer, but it's also apparently the first high performance computer that's entirely water-cooled. Rather than filling rooms with air conditioning units, water is piped around veins in each component, removing heat 4,000 times more efficiently than air. The hot water is then used to heat the buildings of the Leibniz Supercomputing Centre where it lives, saving the facility $1.25 millio