Product ReviewsMotorola SURFboard SB6121 (575319-019-00) 199.68 Mbps

SB6121 PREMOD Forceware v1.4b-mod2

This is a review of the Motorola SB6121 PREMOD w/Forceware cable modem.
If you are looking for one on a stock SB6121, look elsewhere. This is a totally different beast, and NOTHING will work for you.

With that out of the way: It works great for what I wanted. After reading and reading, and reading some ore, I hooked it up, changed a few parameters to let it connect, and success!
Nice and fast, most options are fairly easy to understand, and it works.
Make sure the "Start Mode" is set to "Online", "Tuner CFG" to MT2170, and the "PGA Type" to MT1570.

If your system uses certs, READ ALOT. There are quite a few How-To's out on the Web.

A negative point: It can take awhile for the modem to reboot, and then foe your router to actually get it's DHCP address/etc from the modem, and actually connect to the internet. Just be patient.

NO, I'M NOT AN EXPERT ON THIS FIRMWARE. Don't ask me "How do I...". I'll ignore them. You have to determine if this modem is for you, and how to get it to work.
In my case, I've used alot of SB51XX Premod modems before, so I knew what will work, and what won't for my cable system. READ AND LEARN.

In my case, I could use this one to substitute for my subbed modem, and, using the stock configuration file, have everything humming along nicely.

As far as a DOCSIS 3.0 Modem goes, it works. There are faster and more feature rich models out there (some premodded, some not), but for me and my situation, this one works wonderful.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: orangecountydeals

You get what you pay for

I decided to choose this product rather than the faster modem, the SB6121 due to wanting to save a buck or two and because I live in a 1 bedroom apartment. The internet I receive is fast, adequate when running through the cables, obviously less so through wifi.

All in all I appreciate the modem and it's usefulness. It was easy to set up and has been great thus far.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: p70yuOqQTn2@Del...

Older model but still supported

I purchased this product to be used on COMCAST. The first thing the installation tech said was that it was marked as "end of life", which meant that COMCAST would stop supporting it shortly and I would have to purchase another soon. This concerned me but upon a further conversation with a COMCAST telephone-support tech, I was told that it just meant that COMCAST was no longer selling this model and would not offer tech support for it.

Having said all that, the unit is DOCSIS 3.0 compatible and should work up to 170 mbps. I am only using this modem with 10 mbps service whereas COMCAST is offering up to 2 gbps. If you are only planning to use this unit up to 170 mbps service then this unit is fine.

Peace and blessings.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: us_auctions4u

Cable Modem SB6121

Needed faster internet and cable was the only option. Cable company was charging a rental fee but gave options for me to purchase my own cable modem. Bought this used on Ebay and works great. Very happy with the purchase.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: jeremy289er

Good modem. Happy with purchase so far.

I purchased the modem because (1) my previous one was acting up - dropping access to the internet sporadically, and (2) the SB6121 would support higher speeds should I decide to upgrade my plan in the future. So far, the modem has been solid (I like the design - heat can dissipate well through the honeycomb shell). I rated it Good because I have utilized the modem for less than 1 year.Read full review...

Streaming demon

Set up with Comcast was a breeze, at least as far as over the phone anyway.
Works well with thru my cisco router as all 4 of my puters wired and two laptops wireless all streaming YouTube or an anime channels at same time.
No choking with this bad boy.
Great and I mean great buy with screaming delivery time too of only two days from purchase.
Impressed I am.
Easy set up, easy activation, easy money as I saves my over a "hundred dollars a year" in rental fees to Comcast.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: ssdealsprime

Good Value

No problems with the unit, set-up was easy and performance is as advertised. I needed a Docsis 3.0 modem to handle 100 meg cable speed and this does unit the job well at a budget price.

Verified purchase:  Yes | Condition: refurbished | Sold by: bluedealz-com

Motorola Arris Cable Modem

The modem arrived quickly and was easy to set up. All I had to do is hook it up to the cable and my wireless router. Then I called the cable company to give them the MAC address of the modem and they did a reset. All is working well. I also have an Ooma hooked up to get my telephone service over the internet. Everything working great so far.Read full review...

Verified purchase:  Yes | Condition: refurbished | Sold by: super-fast-ship...

Great Modem, Great speed

The modem is a great value, I ran a speed test before and after installing the modem. It averages 1.6 mbts to 2.0 mbts quicker and saves me $10 a month on my internet bill. Very easy to setup, plug it in call the cable company and they do the rest.Read full review...

Verified purchase:  Yes | Condition: new | Sold by: best_buy

Does not match with my existing modem

I will return this item when I get back from travel because my existing modem had four plugs/cable on the back. This modem have only three. I'm on travel and be back home end of the month.

Verified purchase:  Yes | Condition: new | Sold by: best_buy