Well - Comcast upgraded the network recently - so basic Silver service is4000/384 and Gold is 6000/768 ($10 / month more).
Many people who had Gold were not getting the speeds they were supposed to. Comcast came back and said it was a limitation of older modems.....below is the post from Comcast on the Comcast Help Forums. A tech over the phone told me that the Surfboard 4100 is not taking the DOCSIS 1.1 upgrade. I have a Surfboard 4100 - which is supposed to be DOCSIS 1.1 Certified. I did not get the Gold speeds - so I dropped to Silver until I can find a deal on a "supported" cable modem. Here are the Surfboard 4100 specs ...
Somehow - you think this would have been tested before a mass rollout - no?
Here is the link to all the supported modems -
Some older modems may not be able to get the top speeds with the latest speed upgrades. Below is a list of these modems and the maximum download speed they are capable of achieving. If you are currently using one of these modems, you will need to upgrade to a newer modem in order to achieve these new higher speeds. Please note that some of these modems are capable of attaining the Silver speed at the 4Mbps speed but will not achieve the 6Mbps of the Gold tier of service.
Modem Modem Max Download Brand Model (Mbps)
----------------------------------------- Motorola SB3100 4.9 Motorola SB4100 4.9 Terayon ECM615 3.8 Terayon ECM715 4.4 Thompson (RCA) DCW615 5.4
If you are currently leasing one of these modems from Comcast, these modems can be exchanged for a newer modem - please contact a customer support representative through Live Chat or at 1-800-COMCAST for assistance with exchanging these modems.
If you currently own one of the above modems, you can continue using this modem but the Max Download speeds shown are an indication of the top speed you will achieve with these modems. In order to achieve the higher speeds of the Gold tier of service, you will need to upgrade to a newer modem or contact Comcast support to inquire about leasing a modem."