Windows 8 tablets, vs. Windows RT, use Intel processors vs. ARM CPUs. That places them at a significant disadvantage battery life-wise. A prime example is the Microsoft Surface Pro tablet, which averages about 4 to 4 1/2 hours of actual battery life.
To be clear, the Clover Trail Atom processors are much better on battery life. They offset that, however, with 32-bit only processing and much slower performance.
To make matters worse for Microsoft's Surface Pro battery life, its Ivy Bridge CPUs required active cooling. The new Haswell processors will not.
Intel has claimed that Haswell dual-core chips will offer up to (with the key phrase being "up to) 50 percent bettery battery life than the Surface Pro's previous CPUs. That seems borne out by Microsoft's own claims about the battery life of the Surface Pro 2, which it says will average two hours more before the battery gives up the ghost (Hint to those without calculators: That's about 50 percent more battery life).
In addition, rumor says that Microsoft is planning to release a new keyboard cover, dubbed Power Cover, which adds a battery to the accessory and thus could extend Surface Pro 2 battery life to a full day. The Power Cover is expected to be backward compatible with the Surface Pro, but not the Surface RT.
Microsoft has scheduled a Surface 2 press event for Sept. 23.
Microsoft's Surface RT and Surface Pro tablets had rather tepid sales, especially when compared to Android tablets and iPads, rather than on their own. Atom-based tablets, suffering from poor performance while having much better battery life (Acer, for example, claims 18 hours of battery life for its Iconia Tab W510 when the keyboard dock is included), sold in similarly so-so ways.
The new processors began shipping ahead of the Intel Developer Forum (IDF), which began Tuesday in San Francisco, Calif. IDF 23013 will focus on mobile products, and Intel is expected to launch new Atom chips, code-named Bay Trail, also for tablets, at the show.