As web and cloud service usage grows so does demand for computers to serve content to huge numbers of users across the globe.
Serving content over the net is often not computationally demanding, but can require a lot of data to be sent to and from the processor.
These tasks — characterised by low CPU demand but high I/O — are well suited to arrays of weedier chips with lower power consumption. The lower processing power of these chips mean fewer clock cycles are going to waste, while the modest power consumption reduces running costs and allows more servers servers to be packed into a cluster.
Demand for these clusters of low power servers has created a market for microservers, servers with CPU power consumption below 10W, withbased on the Intel Atom S1200 family of processors and Arm-based CPUs.
In response to customer demand for lower power consumption, Intel is now pushing down the draw of its other server families towards microserver levels.
Intel has reduced the power consumption of the Xeon E3-1220L v3, the lowest power server in its E3 server processor family, which ranges from low-power models to quad-core 3.6GHz chips.
The Haswell-based E3-1220L v3 server, due to ship in the third quarter of this year, has had its thermal design power (TDP) cut from 16W to 13W, and its clock speed dropped from 1.6GHz to 1.1GHz.
The L-variant of the E3 chips are targetted at "applications where power is a key factor", said an Intel spokeswoman, giving the example of high density configurations and microservers.
"To meet customer needs we will have optimized the frequency/TDP to give best solution for this market segment," she said, explaining the drop in clock speed and power draw.
Demand for ultra-dense servers is the only part of the server market where analyst house IDC is predicting significant growth in the coming years. The firm forecasts 14.2 percent compound annual growth rate in shipments of units of ultra-dense servers between 2008 and 2017, compared to 1.3 percent decline in unit shipments of all other types of servers.
There has also been a steady growth in the development of microservers based around Arm's low-power Risc processors in recent months. Arm-based system-on-a-chips, found in more than 90 percent of mobile phones, are finding a home in servers thanks to their low power consumption, modest cost and integrated components, such as networking.
In June, Mitac International announced it will be releasing a microserver based on the 64-bit Armv8 X-Gene chip. The Mitac 7-Star Arm-based microserver will take 18-blades in a 4U server. Each blade will accept one X-Gene processor, has two DDR3 memory slots and two 3.5-inch SATA 3.0 disc drives. Each server node has two Ethernet ports, one running at 1Gbps and the other at 10Gbps.
UK server maker Avantek also recently launched its first ARM server based on Calxeda's quad-core 32-bit EnergyCore ECX-1000 Series processor. The 3U chassis hold 48 nodes, making for a total of 192 cores running at 1.4GHz and 192GB of RAM system, with an overall power consumption below 150W.
HP plans to release a tranche of Arm-based cartridges for its Moonshot chassis, which can hold up to 450 server nodes, this year. Forthcoming cartridges including a quad processor cartridge using the 32-bit ARM Cortex-A15 based 66AK2H chip from TI, focused on providing digital signal processing to telcos, oil and gas companies and advanced voice analysis for government agencies; as well as a quad processor cartridge using a 32-bit Cortex A9 Calxeda SoC that can scale up to 1,800 nodes per rack.