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Today's data centers are like cities that never sleep, and their power demands never stop growing. High-density computing in data centers and server farms requires an increasing amount of power for artificial intelligence (AI) algorithms and other complex computing applications. The standard power delivery method in traditional server farms is to convert AC input into 12VDC and then feed it into the servers or other information technology (IT) equipment in the server racks.
However, as the power requirements for complex computing applications continue to grow, converting AC to 12VDC becomes a decreasingly efficient delivery system. Converting AC input to 48VDC can increase power density while improving space efficiency overall by reducing the number of power components on the rack. This shift comes with challenges, though, as converting an entire data center or server farm from 12VDC may require significant retrofitting and reorganization of components and systems.
In response to data centers’ growing complexity and energy consumption, The Open Compute Project® (OCP) was founded in 2011 as a collaborative initiative to create and propagate energy-efficient data center hardware designs, improve computing efficiency, and reduce the overall impact of data centers and server farms on the environment. To support those goals, the OCP designed a server rack specifically for 48VDC power distribution. The OCP Open Rack Version 3 (ORv3) can provide data centers with the opportunity to integrate 48VDC components and equipment into server farms and improve overall power and computing efficiency.[1]
In this blog, we explore why data centers are moving to 48V power and detail how BarKlip® Power Cable Assemblies from Amphenol offer a convenient OCP Orv3-complaint solution for the higher density computing requirements of modern data centers.
Distributing power to the various equipment and components on a server rack becomes increasingly challenging as computing applications require higher levels of performance. An individual 12VDC rack supplying power to servers might employ multiple 12V systems that each utilize a busbar to reduce power losses. As a rule of thumb, 12V systems typically become too inefficient to manage when a single rack's power requirement exceeds 15kW. Below 15kW, a 12V system can attain as much as 80 percent power efficiency, but that number drops significantly when power needs go beyond 15kW—all the way down to approximately 64 percent at 36kW. In contrast, 48V power distribution systems can maintain almost 90 percent power efficiency for a rack requiring more than 15kW.
Converting to a 48VDC power distribution system reduces heat and power loss by delivering four times as much voltage. At the same wattage, the current will decrease at the same rate the voltage increases. Four times as much voltage means just 25 percent as much current, which has a significant impact on heat and power loss. Less current also reduces the amount of copper wiring required to distribute power across the rack. 48VDC output cables are significantly thinner than 12V cables— almost 90 percent smaller—and are less costly to manufacture, further reducing data center costs. Converting to 48VDC also means more space on the rack itself for computing components, increasing overall computing density. As such, 48VDC power distribution systems are becoming part of a broader trend in data centers and server farms that are trying to provide power more efficiently while increasing power and computing density.[2]
Server racks distribute power to their various payloads by utilizing power shelves, usually located at the top of the rack above the servers. The power shelves themselves utilize busbars, which are essentially long metal strips, to send power to the rest of the rack. Traditionally, the connection between the busbar and cable sending power to the payload is a frequent source of power loss along the distribution path from the busbar to the cable to the circuit board. Moreover, an unreliable connection between the contact and the wire can increase resistance and reduce overall performance.
Connectors like Amphenol's BarKlip® Power Cable Assemblies can deliver optimized efficiency by reducing power loss at the point of contact and providing ultra-low end-of-life contact resistance. (Figure 1). Amphenol's BarKlip connectors are OCP 48V compatible and designed to meet ORv3 open architecture standards. Offering high current-carrying capabilities and customizable features, the BarKlip connectors are well-suited for use in a variety of power-dense data center applications such as power shelves, baseband Units (BBUs), server/storage sleds, and other high-current applications.
Figure 1: Amphenol FCI BarKlip Power Cable Assemblies feature an ORv3-compliant design that supports high current distribution between busbars, cables, and circuit boards. (Source: Mouser Electronics)
The BarKlip connector systems include two individual power circuits and two secondary chassis grounding contacts. All the contacts are made of a high-conductivity copper alloy, and the connection between the wire and the contact is ultrasonically welded to ensure reliability of the current transition. The direct pluggable connection to the uninsulated busbar also optimizes power efficiency and reduces overall power loss. Additional grounding functionality for safety purposes is another key feature in the BarKlip design, and the ultra-low end-of-life contact resistance that Amphenol's connectors provide—around 0. 0.05mΩ—ensures reliability long after more traditional connectors and distribution systems have begun to degrade. Cost savings will be realized at the point of purchase, with fewer components and less raw material required, while the reliability and durability of BarKlip connectors will reduce replacement and repair costs over the life of the components.
Transitioning from a 12V to a 48V power distribution system will likely require some modification or replacement of existing hardware or cabling, but the end result will be higher power and computing density and significantly reduced power losses. When the goal is to move power to the chip as efficiently as possible, 48VDC distribution is the preferred option. Reducing leakage and power losses will not only improve performance but also save money on the cost of energy in the long run, which has environmental and bottom-line benefits. Efficient and reliable hardware solutions like the BarKlip connector series from Amphenol can help streamline the transition to 48V and maintain consistent system energy delivery from input to payload. As the energy demands of high-power computing applications continue to rise, 48V power distribution will prove to be the optimal delivery method for meeting those needs, and with the right connections, the challenges associated with this transition can be overcome.
Adam Kimmel has nearly 20 years as a practicing engineer, R&D manager, and engineering content writer. He creates white papers, website copy, case studies, and blog posts in vertical markets including automotive, industrial/manufacturing, technology, and electronics. Adam has degrees in chemical and mechanical engineering and is the founder and principal at ASK Consulting Solutions, LLC, an engineering and technology content writing firm.
Sources
[1] https://www.opencompute.org/documents/open-rack-base-specification-version-3-pdf [2] https://www.opencompute.org/files/OCP18-Workshop-Huawei-v2-final.pdf
Amphenol Corporation is a designer, manufacturer, and marketer of electrical, electronic and fiber optic connectors, interconnect systems, and coaxial and flat-ribbon cable. Amphenol Corporation has developed a range of connector and interconnect products for the information technology and communications equipment applications, including the converging voice, video, and data communications markets. The primary end markets for the Company's products are communications and information processing markets, cellular telephone and data communication, information processing systems, commercial aviation, aerospace and military electronics, as well as automotive, rail and other transportation and industrial applications.
