IBM and the Fraunhofer Institute in Berlin are testing a cooling solution for stacked CPUs which involves pumping water through the actual chip in order to limit the temperature of the cores. Traditional coolers which are attached to one side of the chip do not do the trick, IBM said.

This happens because the so-called 3D chips, which are CPUs made of the actual CPU chip of silicon stacked on top of memory chips, need to dissipate around 1 kilowatt, in an area of only 4 square centimeters and a thickness of about 1 millimeter. The new technology shortens the distance information on a chip needs to travel by 1000 times, and allows for the addition of up to 100 times more channels for data transfer.

The technological challenge was to isolate the channels through which water runs, hair-thick, from the electrical connections on the chips. The experts at IBM and the Fraunhofer Institute needed to design a new manufacturing process which ensured the sealing of electrical connections to prevent short-circuits.

Two months ago, IBM has announced a new line of servers targeting Web 2.0 customers, which have a liquid cooled rack back. IBM's liquid cooled machines give up little heat, which also translates in 40 percent smaller electricity bills.