Facebook has targeted a power usage effectiveness rating as low as 1.06 as the social networking giant activated its second self-operated data centre facility last week.

The 16-month, 2000-person project is one of several data centres the company has begun building in and out of the US in a bid to sidestep traditional facility operators in favour of a highly-customised setup.
That includes replacing off-the-shelf blade servers with internally designed equipment to provide "vanity free" operation which the company expects to be 38 percent more efficient at 24 percent less cost than comparable facilities.
Removing non-essential components from servers while improving cooling and power distribution has become core to the company's attempts to completely manage the equipment it uses to run the social networking service for more than 800 million users.
Facebook's newest facility, in Forest City, North Carolina, will become the testbed for version two of the company's Open Compute project, which tracks and publicises the company's ongoing effort to open source new server designs.
The company said in a blog post last week that the newly designed servers would be "some of the first to use Intel's Sandy Bridge processor in production".
The servers and data centre design - including an ambient air cooling setup - would also contribute to Facebook's attempts to reach a PUE measurement for the facility of between 1.06 to 1.08.
Facilities used by rival Google report a similar PUE measurement of 1.06 under "an interpretation commonly used in the industry" but claims an average measurement of 1.14 across all its centres.
Facebook, which is set for a highly anticipated initial public offering on NASDAQ later this year, has reported a significant increase in data centre spend since it began its efforts toward self-operated facilities two years ago.
It spent a total US$1.1 billion on its data centres and contractual commitments for the facilities in 2011, and expected that cost to rise to at least US$1.6 billion this year as it rolls out more of its highly-customised data hubs.
A third facility, mirroring the newly opened Forest City data centre, is expected to be completed this year while further works are scheduled for Oregon near its first data centre and in the Northern Swedish town of Luleå.
Facebook warned investors in February that it expected to "incur increasing costs, in particular for servers, storage, power and data centers" to support its future growth, which may impact profitability.