Editing Blade server (section)

=== Cooling ===
During operation, electrical and mechanical components produce heat, which a system must dissipate to ensure the proper functioning of its components. Most blade enclosures, like most computing systems, remove heat by using [[computer fan|fan]]s.

A frequently underestimated problem when designing high-performance computer systems involves the conflict between the amount of heat a system generates and the ability of its fans to remove the heat. The blade's shared power and cooling means that it does not generate as much heat as traditional servers. {{as of | 2009 | alt = Newer}} blade-enclosures feature variable-speed fans and control logic, or even [[Liquid cooling for computers|liquid cooling system]]s<ref name=sunpowerandcooling>[http://www.sun.com/servers/blades/6000chassis/Blade6000_PowerCooling_WP.pdf Sun Power and Cooling]
</ref><ref name=hpthermal>{{Cite web |url=http://h71028.www7.hp.com/ERC/downloads/4AA0-5820ENW.pdf |title=HP Thermal Logic technology |access-date=2007-04-18 |archive-date=2007-01-23 |archive-url=https://web.archive.org/web/20070123051510/http://h71028.www7.hp.com/ERC/downloads/4AA0-5820ENW.pdf |url-status=dead }}</ref> that adjust to meet the system's cooling requirements.

At the same time, the increased density of blade-server configurations can still result in higher overall demands for cooling with racks populated at over 50% full. This is especially true with early-generation blades. In absolute terms, a fully populated rack of blade servers is likely to require more cooling capacity than a fully populated rack of standard 1U servers. This is because one can fit up to 128 blade servers in the same rack that will only hold 42 1U rack-mount servers.<ref name=density>{{Cite web |url=http://h18004.www1.hp.com/products/servers/proliant-bl/c-class/2x220c-g5/index.html |title=HP BL2x220c |access-date=2008-08-21 |archive-url=https://web.archive.org/web/20080829183852/http://h18004.www1.hp.com/products/servers/proliant-bl/c-class/2x220c-g5/index.html |archive-date=2008-08-29 |url-status=dead }}</ref>