Some people can't believe that Microsoft is working on a version of Windows Server for ARM processors . I only wonder what took the software giant so long.

True, when you think of ARM processors your mind immediately goes to smartphones and tablets, but 64-bit ARM processors can do far, far more than tweet your latest photo to your followers. Server hardware companies such as Dell and HP have been working on 64-bit ARM as a future data center platform for years.

Why? There are numerous reasons that 64-bit ARM server designs are attracting attention.

The bottom line one is that a 64-bit ARM powered microserver has a thermal design power (TDP) of of between 10 and 45 watts. A conventional x86 server runs more than 90 watts. The lower the power consumption the lower the not just the direct server utility bills, but the lower the overall data center running costs.

Let me put it put concrete numbers.

A 64-bit ARM server will use no more half the power of its x86 counterpart. ZDNet estimated that the kilowatt hour cost for commercial use per year per server in 2013 was $731.94. Multiply that by the number of servers in a data center and then divide that number by two.

Since power consumption is often a data center's single greatest cost, that is a tremendous saving.

The Linux vendors saw this coming a mile away. The major business Linux powers, Canonical, Red Hat, and SUSE have had Linux running on 64-bit ARM processors for years now. In May 2013, Red Hat showed, with its Fedora community-based Linux, that Fedora could work well on a cluster of four 24 Viridis high-density ARM servers using Calxeda System Server on a Chip (SoC).

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Red Hat, with AMD, American Megatrends, AppliedMicro, ARM, Cavium, Dell, HP and Linaro, are taking the next step. Under Red Hat's leadership they've started a development project to bring 64-bit ARM to the data center . Before that, Red Hat helped create the ARM's Server Base System Architecture (SBSA), which is designed to help accelerate software development and enable support across multiple 64-bit ARM platforms.

It's not just Red Hat. Ubuntu's parent company Canonical showed earlier this year with AppledMicro that Ubuntu will not just run on 64-bit ARM, it could be used to run an OpenStack cloud .

In short, Linux is leading the way to 64-bit ARM data centers.

Microsoft has no choice but to follow.

Some people, of course, are worried that while part of Linux's stock in trade is being ported to one platform after another, Windows has long been stuck primarily on x86 processors. That's true, but Microsoft has also been working on bringing Windows to ARM for some time.

Admittedly, the most visible of those efforts, Windows RT, has been a failure. But, bringing Windows Server to 64-bit ARM is a lot more important than bringing a Windows 8 variant to a tablet.

After all, as Microsoft's last quarter showed, looking ahead Microsoft will be depending ever more on its growing server and cloud sales for its profits. To maintain that growth, Microsoft has already turned to another Linux-based technology , Docker, to get more applications running on the same server. This too helps Microsoft customers get more server bang from their data center dollar.

Put it all together and moving Windows Server and Azure to 64-bit ARM fits perfectly into both Microsoft's technical and business plans.

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