In an article called "The Price of Performance" in the professional journal ACM Queue, Barroso expressed concern at the cost of providing computers, with electricity overtaking the cost of buying the hardware in the first place.
Running costs are exacerbated because companies generally try to utilize their servers as heavily as possible 24/7, or 8,760 hours a year. Faster processors generate more heat, so computer rooms require extra cooling. This uses more electricity, costing more money.
Of course, there's nothing new about any of this. The late Seymour Cray, the world's greatest supercomputer designer, spent a lot of his time on plumbing. In 1985, he resorted to pumping a non-conducting liquid called Fluorinert over the Cray 2's electronics to cool them. When mainframes ruled the world, IBM packed its mainframe chips in ceramic Thermal Conduction Modules with chilled water flowing through pipes to conduct away the heat. Some of today's high-performance games PCs use similar techniques, and it's still an option for servers -- but no one wants to go back to plumbing.
multiprocessors
Barroso suggests that multiprocessor chips are "the best [and perhaps only] chance to avoid the dire future envisioned above". What has changed recently is that multicore processors -- with more than one processing element on a single die -- have finally entered the mainstream, and many PC manufacturers are now shipping systems with Intel Core Duo processors that deliver more per watt than their forebears.
Indeed, the idea has even reached the home market. Microsoft's Xbox 360 games console has a processor with three IBM PowerPC cores, each of which can run two programming threads: the result is a single chip that can work like six. Sony's forthcoming PlayStation 3 will use an IBM Cell chip with multiple processing elements.
Not even low-power multicore chips will solve the power consumption problem permanently, but they should at least buy us a few years breathing space.
And if people factor the cost of power consumption (and cooling, where required) into their computer purchasing decisions, both for commercial and ecological reasons, this will put pressure on the manufacturers to do even better in the future.
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