Understanding how server power management works

Uptime Intelligence regularly addresses IT infrastructure efficiency, particularly servers, in our reports on data center energy performance and sustainability. Without active contribution from IT operations, facility operations alone will not be able to meet future energy and sustainability demands on data center infrastructure. Purchases of renewable energy and renewable energy certificates will become increasingly — and, in many locations, prohibitively — expensive as demand outstrips supply, making the energy wasted by IT even more costly.

The power efficiency of a server fleet, that is, how much work servers perform for the energy they use, is influenced by multiple factors. Hardware features receive the most attention from IT buyers: the server’s technology generation, the configuration of the system and the selection of power supply or fan settings. The single most significant factor that affects server efficiency, however, is the level at which the servers are typically utilized; a seemingly obvious consideration — and enough for regulators to include it as a reporting requirement in the EU’s new Energy Efficiency Directive (see EED comes into force, creating an enormous task for the industry). Even so, the process of sourcing the correct utilization data for the purposes of power efficiency calculations (as opposed to capacity planning) remains arguably misunderstood (see Tools to watch and improve power use by IT are underused).