Start64!At least one major PC maker is expected to show an Intel "Bay Trail" tablet running 64-bit Windows 8.1 at Mobile World Congress, according to a source familiar with upcoming plans for those tablets.

Hewlett-Packard, Dell, Lenovo, and Samsung are some of the most prominent PC makers to offer Windows 8.1 tablets running on Intel's Bay Trail chip. To date, Windows tablets based on Intel's newest -- and redesigned -- quad-core Atom processor have run in 32-bit mode.

One of the most oft-cited reasons for going 64-bit is to address more memory, beyond the 4GB limit that's typical for 32-bit applications. But there are other reasons too.