"We think the opportunity is really significant. It plays to the strength of our company," Haas said. "We're working with virtually every OEM on the planet excited about Windows on ARM."

Microsoft has built Windows 8 on ARM specifically for the touch interface, and will also include new versions of Microsoft Word, Excel, PowerPoint and OneNote -- collectively called Office 15 -- in Windows 8 on ARM. The applications have been rearchitected for the touch interface and minimized power and resource consumption. Windows 8 also frees up the CPU by unloading many applications, such as video in browser and Metro user interface tasks, to graphics cores.

Microsoft is only working with specific ARM-based chip makers including Nvidia, Qualcomm and Texas Instruments for Windows 8. Just like Nvidia, Qualcomm has already said it is developing the quad-core S4 chip to compete with Intel's x86-based ultrabooks. Both Nvidia and Qualcomm plan to deliver prototype ARM devices running Windows 8 to developers.

Laptop and tablet usage differ, with some needing the best performance, and some needing long battery life, analysts said. Windows 8 was developed with mobile devices in mind, and Nvidia's challenge is to engineer a chip that delivers good performance, but not extreme performance that could hurt battery life.

Graphics will be a significant differentiator, and Nvidia may find it easier to jump into Windows 8 on ARM than competitors TI or Qualcomm, said Dean McCarron, principal analyst at Mercury Research.