Google are promoting a change in the way computer power supplies are engineered (.pdf file) which they say can save 40 billion kilowatt-hours over three years. Not a bad target, eh?
The savings is captured by replacing the multi-voltage output scheme, which is today an antiquated design.
Why then do power supplies continue to be built to produce multiple voltages? The answer is simple: because the standard never changed, and because the actual voltage needs of many chips in a computer change every year as they become more energy efficient themselves. But the changing voltage needs of chips are now met by voltage regulator modules (VRMs) that computer manufacturers put on their motherboards. These VRMs take one of these voltages (say, 5V) and transform them down to the actual voltage needed (say, 1.7V) making multiple voltage output capability of power supplies unnecessary.
Providing multiple output voltages complicates the design of power supplies, and it makes it harder to build efficient power supplies. In essence, manufacturers have to build four different power supplies: one each for +12V, -12V, 5V, and 3.3V outputs.
It’s interesting, Google identified and solved the problem on a corporate scale because it was eating into earnings. I like that they are sharing the finding, a cost savings that sould have been a competitive advantage for them – hopefully the power supply design correction will trickle into the power supply designs of all manufacturers.
