Switched On: Windows ReTreat

Each week Ross Rubin contributes Switched On, a column about consumer technology.

Today's hottest and best-selling tablets and smartphones have one thing in common: they are powered by ARM processors. Offered in such variations as NVIDIA's Tegra, Qualcomm's Snapdragon, Samsung's Exynos and Apple's A6, ARM processors dominate the leading edge of mobile products. At LG's recent announcement of its clever and well-appointed G2 smartphone, much was made of it being the first globally launched phone to include Qualcomm's Snapdragon 800; Android, in contrast, wasn't mentioned once. And the long reach of ARM extends far beyond the bleeding edge. The Hisense Sero 7 Pro -- recently cut to $129 just a few weeks after its launch -- has a Tegra 3 processor while ARM chips from Rockchip and MediaTek power Android tablets at even humbler price points.

For years, Intel has promised it would be competitive with ARM in terms of performance per watt (if not in price). It has made great strides both in its smartphone-focused Atom chips and its performance-oriented Core chips (including Haswell, the CPU behind the MacBook Air's huge gains in battery life), but those in the ARM camp have kept their processors' competitive heat up while keeping their generated heat down.

And so, for the first time since Windows NT made the failed leap to processor architectures such as Alpha, PowerPC and MIPS on the desktop, Windows supported an alternative to the x86 architecture. Like iOS and Android, but unlike previous desktop versions of Windows, Windows RT could not be removed or reinstalled from a disc.

Casting aside backward compatibility, Windows RT has a strange relationship with its x86-based sibling. On one hand, the ARM-based OS has competed with Windows 8 for the mindshare of manufacturers and market share with consumers. On the other hand, it has depended on the sales of Windows 8 to help attract developer attention for "Modern" Windows apps that are its lifeblood. And as it has turned out so far, the lack of apps for Windows RT has more to do with sluggish sales of Windows 8-based touch systems than its own slow sales. Windows RT inspired some of the sleekest PCs with some of the best battery life figures -- particularly when paired with battery-equipped keyboard docks -- that we've ever seen.

And yet, such was the head-scratching response to Windows RT that HP, Acer and Toshiba sat out the operating system altogether. Most other major PC manufacturers bet on one model, usually with an interesting form factor. These included Lenovo's IdeaPad Yoga and ASUS' VivoTab RT. But, with sales flagging, both also offered Intel-based versions of their products. Then, of course, there was Microsoft, which shipped the Surface RT well in advance of its much more expensive Surface Pro. In doing so, it mimicked the pricing distance between Apple's iPad and MacBook Air.

Now ASUS has said that it won't be returning to the Windows RT market. Dell, which made the XPS 10 (a detachable device similar to the VivoTab RT), is in the throes of a privatization that may force it to focus on products with more momentum. As for HP, it has embraced an ARM-based detachable tablet. But, like the ASUS Transformer tablet / keyboard detachables, it runs Android.

Dwindling manufacturer support raises major questions about the future of Windows RT. Next week's Switched On will address a few possible scenarios for the struggling operating system.

Ross Rubin is principal analyst at Reticle Research, a research and advisory firm focusing on consumer technology adoption. He shares commentary at Techspressive and on Twitter at @rossrubin.