With the release of Windows 8, Microsoft has hedged its bets. In an effort to make its OS more suitable for tablets, it simultaneously released RT, the first version of Windows to support the ARM chips found in most smartphones and tablets. While Windows RT promises uncompromising battery life, it's not capable of running "legacy" Windows apps — despite the confusing Desktop mode.
That means every app you currently use on Windows XP, Vista, or 7 won't run on a Windows RT tablet. The benefit of using ARM processors is that they're generally less power-hungry than the "x86" chips found in regular Windows laptops, and so don't need fans to keep them cool.
At the same time, Intel has been quietly working on improving its chips' power efficiency for years, and what started with cheap processors for netbooks has evolved into Clover Trail, its next-generation line of Atoms. Unlike the regular Intel Core processors — such as the Core i5 found in Microsoft's Surface Pro — Clover Trail processors are efficient enough to allow for fanless designs, and Intel says the chips can power regular Windows 8 tablets for ten hours before you'll need a recharge. With Clover Trail, Intel is sending Microsoft the message that there's no need for Windows RT. It promises the best of both worlds: long battery life and full compatibility with the vast Windows ecosystem.