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Motorola SURFboard SB6121 Cable Modem (SB6121)

4.4 4.4 out of 5 stars 11,749 ratings

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Purchase options and add-ons

Brand ARRIS
Internet service provider spectrum, optimum, cox, xfinity
Connectivity Technology Wired
Product Dimensions 6.4"L x 2"W x 8.7"H
Color Black

About this item

  • Compatible with Time Warner Cable, Charter, Cox, Cablevision, and more
  • Not compatible with Verizon FiOS or AT&T U-verse, no longer approved by Comcast Xfinity
  • Requires Cable Iternet Service, if not sure your provider is CABLE call them to confirm
  • BROWN BOX models NOT VALID for this item when sold as New, should report to Amazon immediately and RETURN to Seller
  • Wired modem only, does NOT include WIFI Router or VOIP Telephone adapter. Gigabit Ethernet port to connect to computer or Router for fast downloads.
  • Internet speeds based on your Cable providers service - up to 172 Mbps download and 131 Mbps upload. 4 Download and 4 Upload Channels.
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Ships from and sold by Tempest Keep Ventures.
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$2.99
Get it as soon as Wednesday, Apr 3
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Motorola SURFboard SB6121 Cable Modem (SB6121)
Motorola SURFboard SB6121 Cable Modem (SB6121)
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Price$96.00-8% $119.95
New Price:$130.90
$39.95-10% $197.97
List:$219.99
-36% $64.15
List:$99.99
$119.95
Delivery
Get it as soon as Wednesday, Apr 3
Get it as soon as Wednesday, Apr 3
Get it as soon as Wednesday, Apr 3
Get it as soon as Wednesday, Apr 3
Get it as soon as Wednesday, Apr 3
Customer Ratings
Easy to install
4.6
3.5
4.2
4.2
4.3
5.0
Tech Support
4.4
3.5
2.9
3.2
3.6
3.7
WiFi signal
4.4
2.5
3.5
3.7
3.9
4.0
Quality of material
4.7
4.2
4.5
Durability
4.2
4.0
4.5
Sold By
Tempest Keep Ventures
Motorola Networking Renewed
Techa Distribution
Verdi!
Books Galore & More LLC
Harom Inc.
connectivity tech
Wired
Ethernet
Ethernet
Ethernet
Wired
ethernet ports
1
1
2
3
3
number of ports
4
1
2
2
data transfer rate
160 megabits per second
3.8 gigabits per second
2500 megabits per second
343 megabits per second
max downstream rate
172 megabits per second
960 megabits per second
2500 megabits per second
131 megabits per second
max upstream rate
132 megabits per second
3.8 gigabits per second
960 megabits per second
2.5 gigabits per second
343 megabits per second

From the manufacturer

ARRIS SURFboard

Since 1997, when the first SURFboard was launched in Retail, SURFboard modems have been amongst the leading modems in the market and saving consumers money on their monthly rental fees.

When you choose an ARRIS SURFboard, you’re joining a 60-year legacy of innovation from the company that invented digital TV and brought wireless Internet into the home with the first cable modem gateway. The same company that the world’s leading service providers choose to connect millions of people around the world to the Internet.

Harness the power of SURFboard and take control of your home network!

SURF with the original and save money!

A lightning-fast Internet experience like no other. The SURFboard SBG6700-AC is 3 products in 1: a DOCSIS 3.0 Cable Modem, Dual-Band Concurrent 802.11ac Wi-Fi Access Point and 2-Port Gigabit Ethernet Router. With download speeds up to 343 Mbps and Wi-Fi speeds up to 1600 Mbps your gaming and video streaming just got better! Beamforming technology provides maximum Wi-Fi coverage and performance. Stop paying rental fees. Own yours today!

Amazing Features

  • DOCSIS 3.0 Cable Modem
  • Download speeds up to 343 Mbps
  • 8 download & 4 upload channels
  • 2 – Gigabit Ethernet Ports – 10/100/1000 Mbps
  • 2.4/5.0 Ghz Dual-band concurrent
  • 802.11ac W-Fi speeds up to 1600 Mbps
  • Supports IPv4 and IPv6 – the latest Internet standard
  • Wi-Fi beamforming – max coverage & performance
  • Compatible with major U.S. Cable Providers
ARRIS SURFboard Wi-Fi Cable Modem SBG6580 ARRIS SURFboard Wi-Fi Cable Modem SBG6700-AC ARRIS SURFboard Wi-Fi Cable Modem SBG6900-AC
SBG6580 Wi-Fi Modem SBG6700-AC Wi-Fi Modem SBG6900-AC Wi-Fi Modem
Customer Reviews
4.0 out of 5 stars
6,268
3.9 out of 5 stars
1,654
4.2 out of 5 stars
1,469
Download Speed 343 Mbps 343 Mbps 686 Mbps
DOCSIS 3.0 3.0 3.0
Gigabit Ethernet Ports 4 2 4
Wi-Fi N300 dual-switched AC1600 dual-band concurrent AC1900 dual-band concurrent
Pre-set Wi-Fi Security
Wireless Guest Access
Energy Efficient Ethernet
2 Year Limited Warranty
Tech Support by ARRIS

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Product information

Warranty & Support

Product Warranty: For warranty information about this product, please click here [PDF ]

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Motorola

Motorola SURFboard SB6121 Cable Modem (SB6121)


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Product guides and documents

Product Description

Product Description

A new and improved version of the world's most widely deployed DOCSIS cable modems. For the residential cable subscriber who wants a powerful modem capable of delivering a high-speed data service at blazing fast speeds.10 / 100 / 1000 Base-T Ethernet Port (RJ-45) and 1-Year Limited Warranty.

Additional information:

• Requires CABLE Internet Service, if not sure your provider is CABLE call them to confirm
• Compatible with ALL Major CABLE providers like Comcast, Cox, Charter, Time Warner, Mediacom, Bright House

Amazon.com

Customer reviews

4.4 out of 5 stars
4.4 out of 5
11,749 global ratings

Customers say

Customers like the performance, ease of installation, speed, value, and quality of the modem. For example, they mention that it works well, it's easy to setup, and it saves them money. That said, some say it'll reduce costs by 50%.

AI-generated from the text of customer reviews

4,826 customers mention4,342 positive484 negative

Customers like the performance of the networking device. They mention that it works well thus far, has no issues, and works well with their iMac and Apple Airport Extreme Base. They also appreciate the hardware and documentation being accurate. Overall, most are happy with the performance and functionality of the product.

"...much satisfied with the ease of set-up, the awesome speeds, the functionality, and the workmanship...." Read more

"...The hardware worked well and the documentation was, for the most part, accurate. Restrictions weren't enumerated...." Read more

"...Do not let them tell you that you need a different modem. This one works great and saves you a lot of money." Read more

"...I plugged the modem back in and everything worked perfectly and is still today (it's been a couple weeks)...." Read more

2,464 customers mention2,369 positive95 negative

Customers find the installation process of the networking device to be easy. They mention that the situation was hassle-free, the instructions are only one page, and the AC adapter is easy to plug into almost any surge protector or UPS.

"...to get a Motorola SB6120 -- and was very much satisfied with the ease of set-up, the awesome speeds, the functionality, and the workmanship...." Read more

"...It was very easy to set up. Three connections and it was all powered up and set to be activated by my service provider - Comcast...." Read more

"...It was easy to set up and only once have I had to unplug the modem to get internet working, although that may have been a problem with the router...." Read more

"...Install & SetUp was easy. Helped reading comments from Users (Comcast employee) with SB6120...." Read more

1,974 customers mention1,736 positive238 negative

Customers like the speed of the networking device. They mention that it works and their speeds seem to be faster than with the old model. They also say that Chrome loads pages noticeably faster, has good range, and good throughput. Customers also say there's been no stability issues so far and that it gives full Comcast subscription speed (20 Mbps). They say it's quick and reliable, and that installation was a snap.

"...warmer than the SB6120. 3.- Connection speeds, latency, and jitter are better with the SB6121 than the SB6120 -- and WAY faster..." Read more

"...Voila, the hardware works beautifully, and the network speeds are up to spec. Next, the MajicJack issues...." Read more

"...My system is fast, more than 35 on downloads and 7 on uploads...." Read more

"...My throughput is much more consistent and level, and I haven't seen any of the disconnection errors I've seen repeatedly with my older (DOCSIS 1.0)..." Read more

1,824 customers mention1,771 positive53 negative

Customers appreciate the value of the modem. They say it's worth the money, and it saves them money every month. Customers also say that it pays for itself in 9 months and eliminates stupid modem rental fees.

"...It's possible to reduce costs by 50% and obtain better service." Read more

"...you are a Comcast user be ready for a bit of a battle, but the product is worth it and saves you a lot of money from renting one from Comcast...." Read more

"...same modem -- I'm not sure that it's the best modem, but again, it is affordable and it is one of only a few that Time Warner will allow you to use..." Read more

"...Best one available out of about 50 different types and the price is better then right, here on Amazon...." Read more

1,156 customers mention982 positive174 negative

Customers like the quality of the modem. They mention it's a fantastic, reliable, and simple modem that delivers a superior experience. They say it'll work with their ISP and is compatible with their network adapters. Customers also say the tech was helpful and courteous.

"...and tested my modem. All the lights were lit as specified and the modem tested fine...." Read more

"This is an excellent modem. Does everything the manufacturer says it does. I just got Amazon Prime, so delivery was very fast...." Read more

"...this replacement modem, but it was painless and the tech was very helpful and courteous. I just wish TW would improve their internet cable speed...." Read more

"Bottom line: this is a great modem and it works with Comcast. Comcast just doesn't have its act together...." Read more

878 customers mention757 positive121 negative

Customers like the stability of the networking device. They say it's rock solid, reliable, and well built. Some say that it has been working solid for almost a month now, without problems. Overall, customers are happy with the quality of the product and are impressed with its speed.

"...the ease of set-up, the awesome speeds, the functionality, and the workmanship...." Read more

"...Just better quality. Long review. The modem works great. Little heat which is an issue in my office." Read more

"...Motorola modems are solid.-Practically dummy-proof. Just make sure it's plugged-in, and wait for the lights to be green/blue or amber...." Read more

"...So, there is a nice bump in speed. There's been no stability issues so far. I'll update this review with any long term observations." Read more

984 customers mention481 positive503 negative

Customers are mixed about the connectivity of the modem. Some mention that it works as advertised, providing a better quality connection. However, others say that they started having connectivity issues a year after purchase.

"...If the Modem's signal is solid and constant, but the power level readings are 5 points off in either direction, check your OUTDOOR SPLITTERS or TAPS..." Read more

"...opinion, I didn't find it easy to use; it would accept only ten digit phone numbers. After two iterations, I was satisfied with the results...." Read more

"...price in the long run, ease of setup, and long periods of internet without interruption, I give this modem 4 stars...." Read more

"...After about a year, I started having connectivity issues. I assumed it was the internet service and not the router...." Read more

381 customers mention260 positive121 negative

Customers are mixed about the compatibility of the networking device. Some mention that it works with Comcast, Time Warner Cable, and other providers. However, others say that it was difficult to get it registered with Comcaster and that it never showed up on their network.

"Bottom line: this is a great modem and it works with Comcast. Comcast just doesn't have its act together...." Read more

"...The modem works with Time warner cable and it sets up quickly - can't say the same for time warner...." Read more

"...me that the device isn't on the "approved list" and thus cannot be activated on their system. This, of course, is PATENT NONSENSE...." Read more

"...This will pay for itself in less than a year. This modem is Time Warner Cable approved...." Read more

This is the sweet spot in current modems.
5 Stars
This is the sweet spot in current modems.
After researching for a while I managed to finally find a modem that does exactly what I needed it to do. Just an fyi, per Comcast, "Special Note on this Device, Only purchased SB6121 retail devices will continue to be activated on our network. The Comcast leased version of this device will no longer be activated." What all that means is that as long as you buy this on your own you can still use it with them. Which makes sense cause if you keep renting from them you will end up paying $10 per month for as long as you own it, or $120 a year. I bought mine Used in Very Good Shape for about $35 which is a steal vs $70 new, still good. So basically, the perks of having this modem are that it meets Docsis 3.0 which is what Comcast requires, it goes up to 172 Mbps which is pretty high, and with your own modem without built in wireless gateway you get to buy your own router that supports the speed and range you need. Now you might think the SB6141 is a better buy, and it's not bad, just more money and a higher data speed cap of 343 Mbps, which isn't bad but it's very expensive to pay for those kinds of speeds from Comcast. Realistically most people myself included can get by on just 25 Mbps. Now think about it this way, this modem can support 172, and I pay for 25 at $40 a month yet get 30 Mbps. So why pay for more in Modem if you aren't going to get that speed from your provider. We use on average about 750GB's per month too. 1 smart tv, 2 smart phones, 1 tablet, 1 desktop, 1 laptop, 2 wireless printers, all on an AC router. We do heavy streaming and downloading and gaming. So overall, it’s small, easy to setup (just a phone call to Comcast and give them the MAC address), and inexpensive modem that has been on for roughly 6 months now straight and not given me a single issue. It reboots very quickly and is easy to navigate once inside even for the most non experienced users. Buy it and don’t look back, especially if you can get a good deal used on it, oh and be sure to use Cat 6 and up cables for the best connection.
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5.0 out of 5 stars great quality
Reviewed in Canada on February 13, 2024
Etienne Ringuet
5.0 out of 5 stars Works with Teksavvy
Reviewed in Canada on September 20, 2013
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Levi Panipak
4.0 out of 5 stars Activated or not let customers know that.
Reviewed in Canada on August 9, 2019
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Harry
5.0 out of 5 stars Fast Shipping !
Reviewed in Canada on June 28, 2013
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Martin Desrochers
5.0 out of 5 stars Très bien
Reviewed in Canada on August 11, 2019