The heat's on to get the power down in the microserver market

The scale of data centres is immense and their power consumption is equally large; some installations require more than 100MW and it's no surprise there was talk of the likes of Google building their own power stations alongside them. As power becomes more expensive and environmental concerns grow, data centre operators want to cut their power consumption. Part of that energy is used by the computers themselves, but an equal amount of power is needed to keep the servers cool. If chips can be developed which dissipate less power, then less power will be needed to keep data centres cool. With this in mind, the server market is shaping up for a fight between ARM and Intel. It's a lucrative market in which Intel already has a major interest, but one in which ARM is gaining a foothold on the basis of energy efficiency; the thinking goes along the lines that lots of smaller ARM based chips will do the same amount of processing as fewer larger Intel chips while consuming less power. ARM launched the Cortex-A15 scalable multicore processor in September 2010, targeting the core at applications ranging from smartphones upwards. But there is little doubt that it has servers in its sights, or at least servers are in the sights of those who license the core. The reason? Those licensees believe they can build multicore server chips that consume less than 10W. That compares favourably to the 40W dissipated by Intel's Xeon processor. While a number of companies have licensed the Cortex-A15 core, products are still in the early stages of development, so current offerings are based on the older Cortex-A9 architecture. Calxeda, in which ARM is an investor, is an example. Operating almost entirely in stealth mode until recently, Calxeda says it is shortly to unveil a quad core Cortex-A9 based chip which will consume less than 5W. System builders have also taken up the challenge: ZT Systems has used eight Spear 1310 cpus from STMicroelectronics to create a 1U server than draws less than 80W. The Spear 1310 is based on a dual core Cortex-A9 processor. Meanwhile, taking a slightly different route is Marvell with the Armada XP (see NE, 22 Feb 2011) range – which includes single, dual and quad core parts. This is based on ARM technology acquired when it bought the xScale portfolio from Intel. Intel, for its part, points to a number of customers addressing what it describes as microserver applications. These include Dell, which is building Xeon based servers with 8 or 12 processors in a 3U chassis; Tyan, which has put 18 single Xeon processors into a 4U chassis; and SeaMicro, which has included 512 Atom N570 cores in a 10U chassis. This latter example is said to consume 25% of the power and require 25% of the space of current servers. And there is one company plotting its own course by developing server chips based on its technology. Tilera says it has created a 'revolutionary' new chip architecture that can support 'hundreds of cores' on one chip. Tilera's says its approach addresses three big challenges: high performance; power efficiency; and ease of programming. Intel isn't letting this potentially lucrative market sector out of its sights and has announced plans for an Atom based server chip which will draw less than 10W. This part, planned for availability in 2012, will be aimed at those applications where low power and high density are important. Even so, Intel doesn't expect this sector to represent more than 10% of the overall server market. An important boost for those looking to take the ARM route came earlier this year, when Microsoft announced that the next release of Windows would support the ARM architecture. But the ARM architecture has one big stumbling block; it currently only supports 32bit operations. Intel, by contrast, offers 64bit capability. There are, as yet, no signs that ARM is addressing this issue and, even if it is, it will be some time before such products reach the market.