power-efficiency & non-x86 desktop systems

["elijah rutschman" <elijahr@gmail.com>]

Hello,

I have recently heard that ARM CPU's tend to be more power efficient
than x86 CPU's.
I know that several free operating systems, Debian GNU/Linux included,
support some non-x86 architectures, such as ARM and MIPS.

So, this brought 2 questions to mind:
Which processor architecture, or specifically, which CPU lines are
specifically designed to be power-efficient?

Are there any non-x86 motherboards with PCI, SATA, USB, etc. that
would be powerful enough for moderate desktop use, i.e. web surfing,
compiling software packages, and playing movies?

Thanks,

Elijah Rutschman
--
http://elijahr.blogspot.com