replace a Comcast Scientific Atlantic modem -lrb- lease for $ 7 per month ... -rrb- with this DOCSIS 3.0 modem which be the highest recommend and certify on the Comcast site -lrb- https:\/\/customer.comcast.com\/help-and-support\/internet\/list-of-approved-cable-modems\/ -rrb- . my speed be now 20mbps d\/l and 4mbp u\/l -lrb- base on speakeasy\/speedtest which I understand may not be the most reliable -rrb- . I be happy with that since I only subscribe to the `` Performance Starter '' level of internet service from comcast\/xfinity -lrb- $ 45.95 \/ mo in ag , Georgia . -rrb- . so at the former $ 7 per month lease , this cable modem will pay for itself within a year . it have be quite reliable and my only reservation be the amount of heat it generate relative to the previous , smaller-size cable modem .