Liquid cooling has been becoming more and more mainstream, thanks in part to closed-system water cooling units. IBM didn't want supercomputers left out so they designed a water cooling system for Europe's most powerful supercomputer. However, things become just a bit tougher when you start dealing with 18,000 processors compared to one or two.
The supercomputer sports 18,000 Xeon processors along with 324TB of memory. Both the processors and the memory are liquid cooled in this new system. The genius behind this system is that it cuts down on cooling costs for the supercomputer as well as cutting down on heating costs for the surrounding buildings.
It does this by heating the water to 45*C and then by pumping it through an exchanger which provides heat for the surrounding buildings. This water cooling system can, according to IBM, result in a 40% reduction of power usage which is good for up to 1 million euros. This is just the start of liquid cooling for IBM as they want to put the coolant pathways directly into the chip.