How to utilize Comcast's high-speed internet with Cisco Router?

Well since you have a router, it is splitting the connection. In other words if you have 8mbs download the router splits the connection for how many computers you have. You can try logging into the router and changing some of the settings, "Google your cisco router and bandwidth," but you wont see much improvement. If your only using two computers you should be able to use a switch. Most IPS allow up to 3 devise on per modem. Check with them.