Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem
Review by noelbeast : Comcast Customer Review/Gamer Review

As a Comcast Customer, I'm sure I wasn't the only person annoyed by the modem rental increase at the beginning of the year (2011). I never really thought about it before, but I was paying more per year to rent an old DOCSIS 2.0 modem Comcast gave me (which had likely been in countless homes before my own) than I'd spend one time to purchase my own. So, I decided to ditch the rental and own.

At first, I thought I'd just buy what I already had: a Motorola SURFboard SB5120 DOCSIS 2.0. So glad I didn't! Instead I shelled out a bit more money and picked up the Motorola SB6120 SURFboard DOCSIS 3.0.

I read the reviews on Amazon prior to purchase, but was skeptical about the claims of increased speed with this modem. It didn't make sense to me, as I'm paying for an internet package with certain limitations on download/upload speed. It only seemed logical that better technology wouldn't be able to surpass limitations the package I pay for has in place. But in the end, what drove me to choose the SB6120 over the SB5120 was the idea of future-proofing; if I'm paying for it, I might as well get the better option.

Once I had the SB6120 running as my own modem, however, I was pleasantly surprised. My Comcast Internet package deal, which has not changed throughout my recent modem replacement, is as follows: Performance 12 Mbps download/2 Mbps upload with powerboost. Also, my area supports DOCSIS 3.0, so my package, utilizing a DOCSIS 3.0 modem, would automatically increase to 15/3 with powerboost. I took some speed tests (speedtest.net) before and after the new modem, and here's what I got on average:

SB5120 DOCSIS 2.0 Modem:
12 Mbps/2 Mbps

SB6120 DOCSIS 3.0 Modem:
20 Mbps/3 Mbps

Now, is this definitive proof that the SB6120 performs miracles with your internet speed? To many, I'm sure it's debatable. I've read a lot online about how people similar to me (similar internet packages) are getting increased speeds with a DOCSIS 3.0 modem, but there's always someone who quickly dismisses such claims as lies (they typically site powerboost as the cause for such "speed increases").

For me, I don't know. All I can say is that, with my set-up (note: I'm a gamer and run a PS3), I now have a faster internet connection with my new DOCSIS 3.0 modem, which mean the games I play online are blazing fast. Perhaps the old 2.0 was junk, perhaps something else, but the one thing I know for certain is that all I did was update my modem. I'm very satisfied with this purchase.

EDIT: As of 01/22/11, there have been no issues with modem. Have not had to powercycle or reset modem for any reason. Setting up with Comcast was a bit of a pain--was transferred to the wrong department twice, and the directions I received from the technician I spoke with were unclear, but since successfully completing set-up of modem, have had no issues whatsoever.

EDIT: As of 01/31/11: Modem went offline for at least 11 hours after 5 days of uninterrupted connection (occurred on 01/26). Location: Colorado. Recently read 2 other reviews by Comcast customers using this modem in Colorado, and they are not happy. Other than being offline on the 26th for several hours, no other issues to date. Previous modem would also go offline for hours on occasion, so I believe it has to be my connection. Still happy with the equipment. It can work in Colorado.

EDIT: As of 03/12/11: This will be my last update unless the modem malfunctions. Since January 26, 2011, no issues whatsoever to report. I have read that modem may have issues being plugged into a powerstip, and that instead modem should be plugged directly into wall outlet. Modem was actually plugged into wall outlet on the 26th when only issue occurred; since then, have had unit plugged into powerstrip, and again, no issues.

Lastly, read that increase in speed may be due to internet provider's lax perameter's with service during update to DOCSIS 3.0. Apparently, once conversion is complete and Comcast has a better handle on things, download/upload speeds should be more strictly enforced, thus: you get what you pay for and even this unit won't work miracles with speed increases. We'll see.

Note: This modem was selling for $75 new on Amazon back in January. Sorry to see that they've jacked the price up so high, but glad I bought mine when I did.

Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem
Review by Joseph Alegre "Joe Review" : The Game player review

I bought this modem the other day because I felt my old SB5101 modem was not optimized for speed. I have a regular DOCSIS 2.0 service through Comcast. The modem made a huge impression on me after it was installed. The download and upload increased around 20 percent. The amazing thing is that this modem squeeze extra bandwidth out of your existing service (weather you have a standard basic megabyte connection or the newer DOCSIS 3.0 service high speed connection). The noticeable difference was the latency speed of the connection. When I click on a link on a web page, the page loads up as soon as the link is clicked. My old SB5101 modem would take a few extra milliseconds to load. What does this mean? If you play video games like Halo 3 via X-box or Call of duty, you will have a reaction time advantage against your competition. The clear negative of this product is that it takes longer to boot-up. If you power cycle the modem or if your internet service provider resets the modem, it will take two minutes to restart. It will take Comcast longer to recognize the modem when you call in to give the Mac address because when they reset the modem remotely, it will take two minutes for the modem to initialize. Once it is online it performs flawlessly. Anyone that buys this modem will benefit from the extra tweaks it has regardless if the are using a basic or super high speed internet service.

Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem
Review by Gene B. : Future Proof!

I bought this modem to replace the ever popular Linksys BEFCMU10 modem I've had for 6 years. I bought a new modem because the Linksys was only DOCSIS 1.1 capable. I am with Comcast, and though my area is still only using DOCSIS 2.0, I figured I would go ahead and get this modem looking to the future upgrade to 3.0. The installation of this modem was very simple, and I simplty had to give my ISP the customer serial and MAC numbers for correct provisioning. My areas fastest tier is 16/2, but I consistantly get 20/6 out of this modem. I would definitely recommend purchasing this modem if you are in a DOCSIS 3.0 area, and especially if you are currently on 2.0.

Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem
Review by Tarun Chachra "Tarun Chachra" : PERFECTION, for Docsis 3.0 Installations

I was renting a modem from Comcast for $4 per month which really was horrible. The modem would crash, reboot, not work, etc... I spoke to some Comcast tech's on Twitter and they recommended I go and buy this modem since it was not yet being distributed by them in my area. Voila, off to Amazon I went.

I purchased the modem, it arrived the next day. I turned everything off....router, computer, etc. The setup was as follows:

A. Plug cable into new modem.
B. Plug ethernet cable from modem to your computer (first time only).
C. Power up modem.
D. Power up computer.
E. For Comcast - Web page comes up that allows you to change your modem.
F. Enter some details....ie. your account number, etc.
G. DONE....shutdown modem, and plug ethernet cable to Router.
H. Enjoy DOCSIS 3.0

I have had this thing for a few weeks now and it works perfectly well on a daily basis. We are actually getting what we pay for...which was not the case with the old junk that comcast provided. We are getting about 60mbps down and 12mbps up...on a good day.

Motorola has an excellent modem again..