That's probably overpowered for the application, you could probably just use 1 CPU, not sure how much power that would save though. The RAM might not be doing much good either, but I don't know if Smoothwall has some way of making use of it.
I have a dual slot-2 HP which uses way more power than I'd like, over 100W idle from what I remember. But it's stuck with P2 based CPUs, which probably take more power than the Coppermine based ones do even at twice the clock speed.

Those Xeons are about 40W TDP each. For a home router with that sort of connection speed, that system is certainly major overkill, both on power, and on power consumption.

IMO the best choice for such a thing, if you're going to use older hardware, would be a single Coppermine Celeron, 600mhz or so. That's still plenty of CPU power, but at ~15W TDP. An i810 motherboard would be a good platform for it, since the integrated video draws less than most dedicated cards, plus there's no SCSI controller and such that you won't need anyway. And the 512MB RAM limit would still allow sufficient memory for such duties. I don't know how well Smoothwall would get along on such hardware, but there are other, lighter systems like pfsense and zeroshell.

FWIW, I have a P3 600(maybe 650 I forget) 440bx I use with pfsense. With my kill-a-watt meter, it uses 30W. It used 35W before I replaced the hard disk with a microdrive. Those Xeons do idle hot, so finding a P3 would be a good idea. BTW, pfsense appears to work great for me with only 128mb of RAM.

Edit: of course the best thing to do is to get an Alix. But when you're only saving $25-30W, it will take 3 years for the Alix to pay for itself.

Oh I know full well it is overkill. And it draws a good amount of power. I could have used my dual slot 1, an intel or840. As for the heat, its in my basement and I tell myself the heat will keep it warmer down there so the furnace doesnt need to work ss hard

Hatta wrote:

FWIW, I have a P3 600(maybe 650 I forget) 440bx I use with pfsense. With my kill-a-watt meter, it uses 30W. It used 35W before I replaced the hard disk with a microdrive. Those Xeons do idle hot, so finding a P3 would be a good idea. BTW, pfsense appears to work great for me with only 128mb of RAM.

Edit: of course the best thing to do is to get an Alix. But when you're only saving $25-30W, it will take 3 years for the Alix to pay for itself.

They only idle hot if you have bad airflow, otherwise they're not that bad. My 700/1MBs @ 784Mhz idle at 32C, but they have a constant high airflow across the heatsinks and right out the back of the case.