Server clusters based on ultra-efficient ARM-designed processors may soon bring significant power savings to data centers.
British chip designer ARM has been going from strength to strength in recent years. Much of its success has been a result of the booming market in mobile devices. Most of Apple’s iOS devices contain a variant on ARM chip designs, as do many other popular smart phones and tablets.
Key to their dominance of the mobile market is ARM’s expertise in designing chips with extremely low power consumption. Battery technology has lagged when compared to the other components of mobile devices and the two most important factors in maintaining battery life are low-powered chips and power management.
Mobile is not the only domain in which power consumption is a concern. Internet giants like Facebook and Google, as well as smaller data center providers, face huge power bills, both to drive their server’s processors and to cool them.
ARM, its manufacturing partners, and companies like Facebook, have been working on solutions that would bring the power efficiency of ARM chips to the server.
One potential use of ARM SOCs (systems on a chip) would be in devices that are specially manufactured to optimize their performance for specific tasks. HP, Facebook, and ARM will soon be releasing a paper that discusses the potential for creating dedicated ARM devices for running memcached. Memcached is a popular key value cache that is crucial to enabling responsive data delivery for huge web services.
At the other end of the server scale, chip manufacturer Calxeda is building general purpose servers that utilize clusters of ARM’s Cortex-A9 SoCs inside a rack mounted chassis. Calxeda’s EnergyCards contain 4 quad-core Cortex A-9 SoCs on a board with 4 DIMMS.
For their Boston Viridis server, Calxeda mounted multiple EnergyCards within a server unit. As AnandTech points out, each unit is in fact a server cluster, made up of multiple SoCs each with its own memory and access to 4 SATA ports.
AnandTech tested a Boston Viridis with 6 EnergyCards. Their reviewer concluded that:
The real-world tests are stunning. Not only does Calxeda’s array of “wimpy” cores outperform Xeon processors in web server tests, it beats them in both raw performance and performance-per-watt. De Gelas writes that “the Calxeda’s ECX-1000 server node is revolutionary technology.
ARM in the data center is still in the early stages of development, but so far, with the potential introduction of ARM devices highly optimized for running common applications and the apparently excellent performance of Calxeda’s ARM SoC-based clusters, it might be time for Intel to start worrying.