On Mon, 22 Nov 2010, Robert Heller wrote:
One *simple* option would be to get a "small" IDE (I assume the existing router machine is IDE based) SSD (or a 32G Compact Flash card + IDE adaptor -- see eBay) and replace the IDE hard drive with this and pull out the case fan (or just unplug its power connector). Remove its keyboard / mouse / monitor. Much of the noise and power use is the disk drive and fan (for the disk drive).
Really? Even a meaty 3.5" drive will be less than 10W, and you're between 4 and 5 for a low power unit. Something like a 1Tb Samsung Ecogreen is around 4.3W. The CPU in the system is going to draw a whole lot more than that. But face it, if it's just acting as a router, it can completely spin that down after boot anyway.
CPU and motherboard contribute a fair whack to the power consumption.
I've no specific recommendations, but clearly something like the following gets you close.
http://www.simtec.co.uk/products/EB2410ITX/
Get the gold board and you've got twin 10/100Mbit network, 128Mbyte RAM, various ways of connecting extra storage, and a 2.3W maximum power draw.
That compares rather well with the old Pentium 4 you're likely to have knocking round which draws about 70W typically just for the CPU...
jh