Well, it depends on quite a few things. One of them is how many people around your house/area also have a cable modem. If everyone around you does, it's going to be slow. Also, it depends on what times you are going online. I have a cable modem, and it's slow for me at peak times, like 7-10pm at nights.
I really don't know if there is anything you can do to make it go faster, but it just may be that so many people are using cable modems. It also may be that when you first got it, you were amazed at the speed, and now the speed
might be the same, and it's just amazing you anymore, so to you it seems slow.
So yeah, I really don't know what to do
