Customer Ratings & Reviews

Meets the new DOCSIS 3.0 requirements of my cable company (Comcast). Easy to connect and install. Just hooked it up and Comcast recognized it and it was online and fully functional in less than 15 minutes without talking directly to any support personnel.

Upgraded from the SB5101 ot this SB6121 and it tripled my speed. I went from 10Mbps to 32Mbps download, and 2Mbps to 5 Mbps upload speeds on speedtest.net. Doesn't get hot like people say it does and its basically the same size as the 5101 "old school" modem. Had to call Cox to help get it connected, took like 15 mins and I was good.

I bought this Modem over two months ago. It was easy to set up. It has been working well ever since.

Easy setup, got a huge bump in speed both up and down over my DOCSIS 2.0 modem.

Great reason to buy this is so you do not have to rent from a cable company. This is the same one we were renting and it works great. There is no problem with modem what so ever. Definitely buy it and save yourself some money.

This is a lot faster than the modem that Time Warner cable provides - Time Warner provides a Docsys 2.0 and this is Docsys 3.0. Time warner also charges a minimum $ 5 fee per month on their modem and this was a one time purchase of $79 and it has almost paid for itself - and I don't have to deal with Time Warner and their modems - that we replaced 3 times in a year period. This one is still working good and it has only lost connection once and we had to unplug it, wait a couple of minutes and reconnect power.

We have not had any problems with this modem! It is very fast and reliable.

Have had no problems with this modem. The installation took longer then expected. I had to call my Internet service provider to make sure they had the correct information (the information that I had already given them). After the modem did its thing for about 15 minutes it started working correctly. I have not had a problem ever since!

I ordered it on line, picked it up at the store, plugged it in and have had no problems with it! Works great! I read the reviews on most all the products I buy on line, and even at retail stores, and thank all of you that supply the reviews of products. It's very helpful! This product has worked perfectly since I turned it on and I have no complaints.

I'm very pleased with this modem and would buy again. It provides a consistently solid connection from Charter, my ISP. I have read that ISPs tend to upload their own customized firmware to the modem and that there can be major stability issues with Comcast. Make sure to keep the modem in a pretty well ventilated location as it does put off some heat. You might also need to call your ISP and provide the MAC address listed on the bottom of the modem for a successful internet connection to be established.

I wanted to replace the old DOCSIS 2 Scientic Atlanta modem I purchased ($25 used) a year ago when TWC increased their monthly modem rental fee to $6/mo. (now $10/mo in my area!) with this model (SB 6121). However, in my county/area it is apparently incompatible with TWC despite being listed at the top of TWC's list of approved modems for "up to" 50 MB/sec plans. Neither TWC online chat support, nor TWC phone support could get it to recieve a downstream connection (although they could "see" it). They scheduled a in home visit 1 day after phone support failed, but the in home tech guy told me (by phone, parked in my driveway to confirm my 8:00-9:00 am appointment) that there was "no way" this model of Motorola modem would work in my county/area (Lorain Co., Oh.). He also offered to give me a $40 credit toward a (~$40 more expensive) modem that would work in our area - the Motorola Model #SBG 6580. Since it also included WiFi N, and I didn't want to switch WiFi routers, I declined the offer (my Apple Airport Extreme WiFi router has too good of coverage in my wide Split level house, and is too reliable to take a chance on the Motorola WiFi.). Since my current ~8 year old modem can handle the max. speed we are paying for ("up to" 20 MB/sec), I'm going to hold off until I REALLY need a DOCSIS 3 modem, when we decide to start paying for a "up to" 50 MB/sec plan. I give it 2 stars (rather than 1) because it may be partly or mostly TWC's fault it doesn't work in our county/area, but it seems to me ANY DOCSIS 3 modem that has up to date firmware (only upgradeable by ISP's now, in this case), and proper specs otherwise, should work.

had to replace current modem due to comcast upgrade to docsis 3.0. couldn't find a cisco that would work with comcast so I looked at the motorola's, had about a month and I am happy with this modem. I am getting the 35g download and 5.5g upload now. I was only getting 22g and 3.4 before with old linksys modem. haven't really had the problem that some have had about it dropping the signal.

5 minute install, works perfectly. Several weeks use with no problems.

Great modem, it works very good. Easy to set up, it has enough power for all my house equipments.

I have no basis for comparison with other modems. Installation was very simple and it worked the first time and flawlessly since.

I like the fact that it is so easy to use and the speed that it supports, I just wish out didn't cost an arm and a leg for it.

I replaced my docsis 2 Ubee with this modem. This modem is the Motorola SB6121 - which the add does not identify unless you look closeup at picture. EZ setup with one call to comcast giving MAC number. I am sad that my connection speed remains the same as with the Ubee. I have docsis 3 in my area, all my gear is compatible. But it won't go faster than 24.5 mbs down and 4.5 mbs up. Oh, by the way, have not been able to connect at Gigabit Ethernet speeds even though all my gear is Gigabit Ethernet.

Easy to use. No issues after four weeks of use. Fast

Great modem, I bought it to use it with my Xfinity X1 service so I wont have to pay the lease fee for using their modem. And this modem is super fast. I hooked it up to my netgear router and I'm getting more speed than what I signed up for. I have Xbox One, Laptop, 2 iphoones, iPad running all the time.

Easy set up and works with comcast cable. Highly recommend product. Good value too.