But this ISN'T that old, craptastic, power-hungry chipset used by most Atom netbooks. It's a new chipset code-named Poulsbo designed specifically to go with Atom. Quoting a tomshardware.com article:
"The Atom Z500 has a TDP that varies between 0.85 W (for the 800 MHz version without HyperThreading) and 2.64 W (for the 1.86 GHz model with HyperThreading enabled). The SCH consumes approximately 2.3 W in its most evolved version, which brings the SCH + CPU together to under 5 W. By comparison with existing solutions, thatâ(TM)s obviously a big step forward â" the Via Nano, for example, is announced at 25 W for the 1.8 GHz version and a Celeron-M ULV at 5 W at 900 MHz."
http://www.tomshardware.com/reviews/intel-atom-cpu,1947-3.html
In addition, the Atom Z-series/Poulsbo combo supports the C6 idle power state where the CPU saves away its architectural state in a small SRAM which remains powered up while the rest of the CPU shuts off entirely. Idle power for the processor is somewhere from .01W - .1 W (this is from what I remember reading somewhere, but I can't find a link right now). Not sure what the chipset's powercomsumption is like when idle.
The biggest known downside to this chipset is that it supports 1 GB of RAM max.