Well, both Shaw and Telus give you multiple IPs on same modem. Has anyone attempted to install multiple NIC on same PC and aggregate bandwidth from separate IPs into one connection by using appropriate software??? do you know upload speed is limited by Modem MAC address or by individual Mac/Ip address of cards connected to it. I suspect you can increase upload/download speed this way???
It's limited by the modem itself. On the Teralink (Terayon) network, the CMTS caps your bandwidth. On the DOCSIS network, the modem itself caps your bandwidth. You can hook 5 computers to the modem with 5 IP addresses, and you'd be sharing the same bandwidth as one computer would.
Now, given that, two computers may be faster, but only because when you're doing one thing on it, it's choking and not fully utilizing your connection, leaving the second computer able to use it all up.