IBM researchers are counting on a 40-year-old technology to keep modern, state-of-the-art data centers running cool and allow companies to squeeze more computing power from the electricity they consume.These considerations are more important than ever. The power consumed by a rack of servers has risen from about 5 kilowatts (kW) of power per server rack five years ago to as much as 30kW today, thanks to the introduction of more powerful processors and denser blade servers. And the power-consumption levels will continue rising in the years ahead."People want more compute power, and we can give it to them because we can package this into a smaller footprint, basically," said Roger Schmidt, chief thermal architect and distinguished engineer at IBM\u2019s server and workstation division.The challenge that Schmidt and his colleagues face is how to dissipate the increasing levels of heat these systems generate. "We\u2019re working on this all the way from the chip to the data center," he said.At the data-center level, Schmidt sees an expanded role for water cooling as a means to bring heat levels down.Water cooling, which uses small pipes filled with distilled or deionized water to dissipate heat, was first used by IBM to cool mainframe computers during the 1960s. The technology, which was used in more than 90 percent of mainframes by the mid-1980s, was given a second lease on life in 2005, when IBM introduced its line of Cool Blue water-cooling products.One such product is IBM\u2019s US$4,299 Rear Door Heat eXchanger, which attaches to the rear of a server rack. Four inches thick and weighing about 32 kilograms (70 pounds) when filled with water, the Rear Door Heat eXchanger can absorb more than half of the heat coming from a server rack, according to IBM.IBM\u2019s water-cooling systems, as well as competing products from companies like Hewlett-Packard, offer several benefits for data centers. Most importantly, water can absorb more heat than air, and the pumps required to circulate water in a cooling system consume less power than air-conditioning systems.And IBM plans to expand its line of water-cooling products in the months ahead. "We\u2019ve got other enhancements coming out shortly," Schmidt said, declining to elaborate on specific details.One potential enhancement is to extend water cooling from the rear of the server rack to specific components, such as processors\u2014as was done with some IBM mainframes. "Once you bring water to the rack, you\u2019ve got a lot of options," Schmidt said.Convincing data center operators to pipe water through racks filled with expensive servers and invaluable data is not always easy. The easiest to convince are those IT managers with experience from the days when water-cooled mainframes were the backbone of large corporations, Schmidt said. But many remain nervous at the thought of water-filled pipes coursing through rooms filled with expensive servers and invaluable data\u2014even though water is already a key component of all data centers."Water cooling in data centers is already there," Schmidt said. "The chilled water that\u2019s brought to the air-conditioning units? That\u2019s water, and it\u2019s in the pipes right above the server racks. We\u2019re just plugging into that to apply that at the rack level."-Sumner Lemon, IDG News Service (Singapore Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.