New Generation of Volume Servers for Cloud Computing
Several companies have been working to create cloud computing volume servers using "wimpy chips". These are low-power, lower-speed chips designed for mobile devices. The idea is that large numbers of these in a server can yield lower energy consumption while maintaining cost-effective performance. The EU has launched an initiative using the wimpy-chip approach, but an American pioneer has shuttered its doors.
SeaMicro introduces itself by noting:
Volume servers consume more than 1% of the total electricity used in the United States—More than $3 Billion dollars each year. Over the last six years, the power consumed by volume servers more than doubled. For companies in the data center, power consumption is the largest Operating Expense...often accounting for more than 30% of Op EX.
SeaMicro's response in 2010 was its SM100000 volume server, which the company claims "Uses ¼ the power and takes ¼ the space of today's best in class..." The company says its array of 512 1.6 GHz Intel Atom CPUs uses less than 2kW of power. The Intel Atom chip is for e-devices, so it is designed to be very power-efficient, which makes it appealing for this kind of application.
ARM chips are an even more popular e-device engine and are said to account for ~90% of all embedded 32-bit RISC CPUs. Calxeda (formerly SmoothStone) was a start-up trying to adopt ARM to volume servers. The company received a $48 million equity infusion in 2010 from a diverse set of investors, including from the investment agency of the Abu Dhabi government and from ARM itself. Three years later, PC World reports that, "Most of Calxeda’s 130 employees will be laid off, except for a skeleton crew that will deal with creditors and figure out how to proceed with the company’s intellectual property." The piece goes on to note, "Calxeda’s departure doesn’t mean the end of ARM server chips."
The opposite of "wimpy" is "brawny". SeaMicro announced in January 2012 "its foray into the world of brawny compute with the immediate availability of the industry’s first fabric-based Intel® Xeon® micro server, the SM10000-XE™…a micro server that uses half the power and one-third the space, but for the first time is targeted at heavy weight workloads as opposed to the light weight ones that are traditionally associated with micro servers."
An alternative approach to "wimpy chips" is to use "wimpy cores" to build energy-efficient volume servers.
The European Union launched in 2012 its Eurocloud server project funded, by the European Commission FP7 Computing Systems Programme. The project, in partnership with ARM, "…relies on the observation emerging Cloud computing application…favour an increase in thread- and memory-level parallelism and benefit little from instruction-level parallelism. Each client request is serviced by a single or multiple independent threads each running on a dedicated processor core. These applications need many simple processor cores with high-bandwidth/low-latency access to very large memories. Using standard off-chip DRAM is bandwidth-constrained due to limited pin count, slow due to chip crossing, and power-hungry due to I/O pads and driving circuitry. To eliminate these inefficiencies and address these issues, we propose to 3D-integrated DRAM chip on top of the ARM Cortex-A9 processor cores and hardware accelerators… Building energy-efficient, compact and environment-friendly data centres will be feasible with energy-conscious 3D server chips."
All these products and projects have the potential for a big impact on clouds' energy consumption and CO2e, but, given the 'brown' nature of today's clouds, data centers will still have to make sure the energy itself is as green as possible.