I'm currently using a TeleWell TW-EA100B USB ADSL modem that has no ADSL2+ support and while it is very reliable device it does consume about 5w. I thought the USB modems would have been lower in consumption than a full router. I've tested a few devices but they typically perform pretty similarly.
I've been hunting for better USB-based options but they seem so difficult to obtain they are not really worth pursuing. Everything based on the st70138 Unicorn II could be good because the chipset manufacturer specifically advertises it as having a very low consumption. Apparently names of devices that have this include Zyxel P-630S EE, ZTE ZXDSL 852 v2, Netronix MN-01 and Acorp [email protected]
The Motorola Netopia 3342N model that has ADSL2+ support (but no USB 2.0 support, which makes it uncapable of actually delivering some of the faster speeds I guess...) should also be an efficient one.
Anyone has one of these and could provide some actual numbers?