i currently have SB5120 and while i was on the phone with comcast trouble shooting some connection issues they mentioned i should upgrade my modem as i'm not getting the max speed i should be. I have a 25MB line and the max my modem can do is 20MB at that is on a good day.
Since i own my modem they wouldn't upgrade me for free or anything but they suggested i go with a SB 6121 or Sb6141. Looking around the 6141 is newer but i dont know much else. Seems to be price $10-25 more as well.
Is the sb6141 my best option here @ $80 off amazon? Or are there others that is compatible with comcast that will be cheaper?
There is a website you need to look at, but a D2 modem [like your SB5120] is capable of more than 20 Mb. I pegged 30 on mine before they sent me my upgrade, I work for comcast. so the rep on the phone is slightly incorrect. No doubt having 4 or 8 channels instead of one will increase your speed, but 20Mb/s is not the limit of a docsis 2 modem nor a 256 Qam channel.
[edit would probably help if I added that website I mentioned
http://http://mydeviceinfo.comcast.net/ ]
the SB6141 does 8/4 bonding the SB6121 only does 4x4 bonding what that means is if its AVAILABLE on the plant [and it may not be] you can bond 8 channels instead of only 4, neither of these makes a difference when only doing 25Mb/s service though, so your safe with either of them unless yo plany to try and subscribe to over 100Mb/s service anytime soon and even then 4 channels will handle the 105 speed we offer, but not the 305, but then the 305 is metro Ethernet [aka fiber] anyway atm so no cable modem is used.
Moto's are pretty decent modems, you will likely be happy with either in the end. Its more like your buying either a camaro or a corvette to drive 45 MPH to work either will go that speed, both are nice cars, both can run way faster than 45MPH, which do you want? The corvette is nicer and faster, if you could just get to the Audubon, but since you can't its overkill for in town driving, then again so is the camaro. One costs about 35K the other about 75K. It is your money, so spend it how you want.
now can you by chance post 192.168.100.1 signal levels and error logs on the current modem, I just want to see if you have a different issue going on for that limited to 20 Mb/s, if I can peg 30 on an SB5101, you should easily peg 25 on one. Perhaps you have an old router after it or are doing wireless g though? In which case these are your choke points not the modem and swapping it without changing these out will not benefit you.
The other thing to consider is if its IPv6 ready though I suspect you have a decade before they force everyone to IP6 since they don't seem to have it anywhere near up and running the world over yet. But IPv4 is on the way out eventually.
