Gemini also reduces power consumption through the use of shared components for functions like networking, management and cooling, HP said, though it isn't providing specifics. It would say only that one Gemini rack will have thousands of Atom CPU cores.

Its secrecy reflects the level of competition in this new area. There's growing interest in building servers with many low-power processor cores as companies look to curb power use in their data centers. Dell is building low-power servers using ARM processors, and SeaMicro already sells servers with Atom chips, though it will likely switch to processors from Advanced Micro Devices, since it was just by that company.

Intel's Atom chips were initially designed for mobile use, but like ARM processors, which also were built for mobile devices, the chips are finding a home in servers for workloads that don't need a lot of computing horsepower.

Centerton is a 64-bit chip that includes several features usually found on server CPUs, including memory correction and support for server virtualization. Current ARM processors are still 32-bit and lack some of those server features, which may be partly why HP ended up releasing an Atom-based server first.

Some server workloads will run on a 32-bit processor but it's "very workload specific," Santeler said, noting that 64-bit ARM CPUs are .