said by kucharsk:I use the CC speed tests as they're the only one (in my experience) Comcast Support considers "official."
How many channels does an SB6120 support? That's what I have.
I was on the same modem, it supports 4 downstream and 4 upstream channels. I bought a Zoom 5341J 8x4 modem a couple weeks ago after the speed upgrade, and I consistently see ~115-120mbps down and ~20mbps up. With the SB6120 it would vary quite a bit. So I think having the additional downstream channels on the Zoom modem helps stabilize the speed.
Edit, here is a speed test I did with my 5341J (Over WiFi believe it or not!)
And a test with my SB6120 a few weeks ago, but same time of day for comparison: