I’ve just read an interesting post on TomsHardware.com about a
solar powered PC . It describes all the steps involved in
creating a modern high-performance low-power computer. They have
a lot of interesting information. One surprising fact (from page
3) is that the PSUs tested (both for AC and DC input) were more
efficient when idle (I expected the greatest efficiency to be
when under load). An AMD processor was chosen due in large part
to the fact that chipsets in suitable motherboards used less
power. For the CPU itself Intel had a competitive offering but
no matching motherboard was power efficient enough (from page
7). Page 8 documents how using a cooling fan (instead of passive
cooling) reduced the power requirements of the CPU to such a
degree that it always saved power use overall. Why do CPUs take
less power when they are cooler? Page 9 mentions that a small
passively cooled video card can draw 88.5W when idle! That sucks
pretty badly, it seems that having a video controller integrated
with the mother