Editing Blade server (section)

=== Power ===
Computers operate over a range of DC voltages, but utilities deliver power as [[Alternating current|AC]], and at higher voltages than required within computers. Converting this current requires one or more [[power supply unit]]s (or PSUs). To ensure that the failure of one power source does not affect the operation of the computer, even entry-level servers often have redundant power supplies, again adding to the bulk and heat output of the design.

The blade enclosure's power supply provides a single power source for all blades within the enclosure. This single power source may come as a power supply in the enclosure or as a dedicated separate PSU supplying DC to multiple enclosures.<ref name=hpblade>{{Cite web |url=http://h18004.www1.hp.com/products/quickspecs/12330_div/12330_div.html |title=HP BladeSystem p-Class Infrastructure |access-date=2006-06-09 |archive-url=https://web.archive.org/web/20060518152828/http://h18004.www1.hp.com/products/quickspecs/12330_div/12330_div.html |archive-date=2006-05-18 |url-status=dead }}</ref><ref name=sunblade>
[http://www.sun.com/blades Sun Blade Modular System]</ref> This setup reduces the number of PSUs required to provide a resilient power supply.

The popularity of blade servers, and their own appetite for power, has led to an increase in the number of rack-mountable [[uninterruptible power supply]] (or UPS) units, including units targeted specifically towards blade servers (such as the [[Eaton BladeUPS|BladeUPS]]).