Calxeda on Friday revealed initial details about its first ARM-based server chip, designed to let companies build low-power servers with up to 480 cores.The Calxeda chip is built on a quad-core ARM processor, and low-power servers could have 120 ARM processing nodes in a 2U box, the company said in an e-mail statement. The chips will be based on ARM's Cortex-A9 processor architecture.With the inclusion of DRAM, each ARM node will consume an average 5 watts of power during operation. The chip will include a fabric to enable communication between the nodes.The company did not share further details such as chip shipment dates or clock speed. ARM processors are used in most of the world's smartphones and tablets. But some chip makers are looking to bring ARM's low-power attributes to servers as companies look to cut energy costs. Calxeda will compete with companies such as Nvidia, which is developing its first ARM CPU, code-named Project Denver, for PCs, servers and supercomputers. Marvell has already announced the quad-core Armada XP server chip, which runs at 1.6GHz and includes memory, networking and storage interfaces.Low-power servers are also being built around selected netbook chips based on the x86 architecture, such as Intel's Atom processor. SeaMicro last month announced the SM10000-64 server, which incorporates 256 Intel Atom N570 dual-core processors. Dell also offers low-power servers based on Via's Nano chip. Advanced Micro Devices is looking to put its low-power Bobcat chips on servers.Servers mostly come with x86 chips, which could be a barrier as chip makers try to push ARM processors into data centers. There are also concerns about the weak server software ecosystem surrounding ARM. Dell this week said companies may find it challenging to maintain separate software stacks, and may be unwilling to port software from x86 to ARM, which have separate instruction sets.The ARM community is in its early days of setting up performance benchmarks, but servers with Calxeda chips should be included in technology plans, said Richard Fichera, principal analyst and vice president at Forrester, in a blog entry posted Friday."Calxeda's performance models that they shared with us appeared to be conservative and to have factored in a generous margin for competitors Intel and AMD to improve their performance-per-watt metrics." Calxeda, which was initially known as Smooth-stone until the name was changed in November, is also building a software ecosystem for servers built around its chips."Once Calxeda powered servers are in the market, software and applications will follow quickly," the company said.