Organizations such as on-line retailers, Internet service providers, search providers, financial institutions, universities, and other computing-intensive organizations often conduct computer operations from large scale computing facilities. Such computing facilities house and accommodate a large amount of server, network, and computer equipment to process, store, and exchange data as needed to carry out an organization's operations. Typically, a computer room of a computing facility includes many server racks. Each server rack, in turn, includes many servers and associated computer equipment.
Some computer systems typically include a number of components that generate waste heat. Such components include printed circuit boards, mass storage devices, power supplies, and processors. For example, some computers with multiple processors may generate 250 watts of waste heat. Some known computer systems include a plurality of such larger, multiple-processor computers that are configured into rack-mounted components, and then are subsequently positioned within a rack system. Some known rack systems include 40 such rack-mounted components and such rack systems will therefore generate as much as 10 kilowatts of waste heat. Moreover, some known data centers include a plurality of such rack systems.
Some computer systems, which may function as servers, include a number of components that are mounted in an interior of the computer systems. The components, which can include printed circuit boards (for example, a motherboard) and mass storage devices, can support one or more components that generate waste heat, referred to herein as “heat-producing components.” For example, a motherboard can support a central processing unit, and mass storage devices can include hard disk drives which include motors and electronic components that generate heat. Mass storage devices can also include solid state drives that generate heat. Some or all of this heat must be removed from the components to maintain continuous operation of a computer system. The amount of heat generated by the central processing units, hard disk drives, etc. within a data room may be substantial. Heat may be removed from the heat-producing components via an airflow flowing through a computer system.
In some cases, cooling systems, including air moving systems, may be used to induce airflow through one or more portions of a data center, including airflow through a rack-mounted server that includes various heat-producing components. However, some servers direct airflow through an interior that includes multiple heat-producing components. Air removes heat from the heat-producing components and in turn the air is heated as it passes through the interiors that include the various heat-producing components, so that air passing over heat-producing components in a downstream portion of the server has a higher temperature than air passing over heat-producing components in an upstream portion of the server. Higher temperatures of the air in the downstream portion of the server may result in reduced heat removal capacity relative to air passing over heat-producing components in the upstream portion of the server. As a result, less heat may be removed from downstream heat-producing components than upstream heat-producing components. In some cases, the downstream heat-producing components are more sensitive to heat than the upstream heat-producing components, which can result in a suboptimal configuration.
In some cases, a computer system mounted in a rack includes one or more hot-pluggable electronic components, which can be added, removed, swapped, etc. from a computer system without powering down the computer system. Hot-pluggable electronic components in a computer system are often mounted at an external side of the computer system, including a “front” side through which cooling air is received into the computer system, to enable simplified access to the components for removal, addition, swapping, etc. In addition, mounting hot-pluggable electronic components to an external side of the computer system enables hot swapping without moving the computer system itself. Mounting hot-pluggable electronic components throughout the depth of the computer system interior can hamper hot-swapping efforts while maintaining operations by other hot-pluggable electronic components. Furthermore, as indicated above, mounting hot-pluggable electronic components throughout the depth of the interior can result in preheating of cooling air which removes heat from some components which are downstream of other components, which can reduce cooling efficiency and can negatively affect component performance.
The various embodiments described herein are susceptible to various modifications and alternative forms. Specific embodiments are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the disclosure to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to.