Second Interview Up at O’Reilly: Barroso on Energy Proportional Computing


Check it out, this is the second audio interview published with O’Reilly. A smaller interview than the Brian Cox interview from last week, but still interesting. Luiz Barroso wrote a very interesting paper with Urs Holzle for IEEE Computing on Energy Proportional Computing, and I took this interview as a chance to ask him some questions.

I’ll summarize it: Most hardware manufacturers build systems to perform well under the SPECpower benchmark which measures the efficiency of a computer at maximum performance. While these specifications look great, they are relatively meaningless when you consider the fact that most (data-center, volume) servers are running at between 15% and 45%. In this range, the computer operates with a terrible efficiency. Full power must be used to keep the disks spinning and the DRAM running, but the CPU is idle for 70% of the time.

He argues that we need to rethink hardware such that components will use energy proportional to the computing they are being asked to perform. If a computer is only operating at 30% utilization…. well… duh… we’d expect it to only use about 30% of the power.

This issue is important as data centers grow from about 1.5% of our total national energy budget to somewhere around 3.0% in 2011.