A cable modem might seem like the last device you'd need to worry about buying. After all, most internet providers include a modem as part of your setup, seemingly saving you the trouble of having to shop for one more device. But in most cases, you're paying for that convenience, as your provider might be charge you a monthly rental fee on your modem. Over time, those charges can really add up. Comcast charges $120 a year if you rent one of its modems. Buy your own, though, and you'll have paid off the cost of that modem in rental fee savings after five to seven months.
For people who'd rather rely on a cable modem of their own, we recommend the. While it has been around for years, the SB6141 still delivers consistent performance while supporting the data-transfer speeds most home users get from their broadband service. Easy-to-interpret indicator lights, compatibility with most major ISPs and a two-year warranty seal the deal for the SB6141.
If you're looking to cut costs even further, Zoom's 5345 cable modem($45) is a solid alternative, if your internet provider supports it. Zoom's model costs less than the SB6141 and also offers a two-year warranty.
For people who subscribe to internet plans that promise download speeds greater than 150 Mbps, we think the Arris Surfboard SB6183 ($85) can handle the job.
Why Buy Your Own Cable Modem
Here's what you'd pay over the course of five years if you rented a cable modem from your ISP instead of buying a $70 cable modem like the Surfboard SB6141.
*Cox rate assumes $10-per-month rental fee for a dual-band modem; Cox subscribers can also rent a single-band modem for $7-per-month or $420 over five years.
Monthly rental fees for cable modems can cost you dearly each year. Comcast charges customers $10 if it supplies them with a cable modem; that's $120 you'd pay out on top of the internet service you also pay for. Time Warner Cable charges customers $8 a month, an annual cost of $96. Those fees have held steady since January 2015, but there's nothing stopping ISPs from hiking up the cost in the future. Buy your own modem, though, and it's already paid for.
It's more complicated for customers who get their internet service from Charter, which bought Time Warner Cable and Bright House last year. (They now operate as Spectrum.) Charter doesn't charge its customers for the modems it supplies; instead it bakes that cost into the overall price of your subscription. That means Charter customers who buy their own modem won't see any cost savings. Time Warner and Bright House both charged monthly rental fees to their customers, but a Charter spokesman told that it will eventually extend its service to those customers, potentially meaning an end to modem lease fees. If you're a Time Warner or Bright House subscriber, you should check with your new ISP to see if there's a timetable for that service rolling out to you before you buy your own modem.
Monthly rental fees for cable modems can cost you dearly each year.
There's also a trade-off when you strike out with a modem of your own. That ISP-provided modem you're renting receives tech support from your internet provider, who will offer a replacement if your current rental ever gives up the ghost. Buy your own modem, and you're on your own for tech support, as far as your cable company is concerned. That's why our cable modem selections promise a two-year warranty.
Should your cable modem provider upgrade your service requiring a new modem, you'll be able to get one for free when you rent. People who own their modem will have to take care of their own upgrades — and some ISPs have been quite pushy about telling users to upgrade their modem.
None of this should dissuade most people from ditching their rented modem — not when $100 or so in annual savings is at stake — but those trade-offs are worth keeping in mind.
What to Look for in a Cable Modem
We focused on DOCSIS 3.0-compatible modems in our testing and research. DOCSIS, or Data Over Cable Services Interface Specification, is a telecommunications standard that cable TV operators use to provide internet service over the same wiring that's serving up your favorite TV shows. Released nearly a decade ago, the DOCSIS 3.0 specification added support for multiple channels to boost speeds.
Major internet providers have already upgraded their services to DOCSIS 3.0, especially for customers who live in heavily populated areas, so having a DOCSIS 3.0-compatible cable modem lets you enjoy improved performance. In the future, internet providers will upgrade to DOCSIS 3.1 and its 1000 Mbps download speeds, but unless you live in one of the few test markets where it's being deployed — Comcast has launched it in four cities — you're better off sticking with a DOCSIS 3.0 modem. That said, if you do live in an area where this higher-speed service is available, a couple companies do offer DOCSIS 3.1 modems capable of taking advantage of faster speeds while also saving you from that monthly cable modem rental fee; we highlight some of the recently announced DOCSIS 3.1 modems in our New & Notables section below.
Besides focusing on DOCSIS 3.0 modems, we also restricted our search to dedicated cable modems. Some manufacturers offer modem-router hybrids, but if any part of those devices fails, you're out both a modem and a router. Having a modem-router combo also complicates upgrading, since routers tend to add support for new networking features at a more rapid clip than modems do. We also test and rate routers, and we can recommend the best router for your needs.
We looked at four factors when determining which modem was the best option.
Compatibility: The most appealing cable modem in the world won't be much good to you if your internet provider doesn't support it. We've listed the compatibility of the modems we've tested with some of the largest internet providers, as well as what tiers of service are supported. (Some modems that work perfectly fine at lower-speed tiers aren't supported if you opt for a faster level of service with your ISP.) Should you decide to buy your own cable modem, you should first confirm with your ISP that your top choice will work with the service you're paying for. Note that the lack of official support doesn't necessarily mean a modem won't work with a given ISP. A modem maker told us that modems that all DOCSIS 3.0-certified by industry R&D firm cable labs should work with a DOCSIS-based internet service.
Design: Most cable modems have the same set of indicator lights: a power light, lights that tell you the status of your send and receive channels, a light indicating whether you have internet connectivity, and a link light that shows if your modem is connected to a computer, router or other device. You'll want a modem that displays these lights in a clear, easy-to-spot way in case you have to troubleshoot any connectivity problems. You'll also want to consider the footprint of a cable modem; a compact design makes it easier for a modem to blend in with your other networking and cable equipment.
Price and Warranty: The primary reason to drop your ISP-supplied modem in favor of one you own outright is to save money over the long term. While that doesn't mean opting for the cheapest modem you can find, you'll still want to look for one with a price tag that's low enough to pay for itself in less than a year with what you'll save in rental fees. Why a year? Because some modem makers provide a year's warranty with their devices, though we favor modems that come with two years of warranty coverage.
Channels: Most of the modems we've evaluated here offer eight download channels and four upload channels, though we also tested a couple of modems that double the number of download channels to 16. The 8 x 4 modems we looked at promise download speeds of 343 Mbps, while the 16 x 4 modems list theoretical download speeds topping 680 Mbps. This is a case, though, where bigger isn't necessary better. Assuming you've got an internet plan that promises download speeds of less than 150 Mbps — and there's a good chance you do — an 8 x 4 modem offers more than enough performance for $10 to $30 less than what you'd pay for a 16 x 4 modem.
Consider internet plans offered by the likes of Comcast and Cox. Both offer a high-speed option — Comcast's Blast Pro promises 200 Mbps download speeds as does Cox's Internet Ultimate. But both ISPs also list less expensive performance tiers where an 8 x 4 modem can handle whatever you throw at it.
Speed Testing: Not Much of an Issue
While we run speed tests on modems, we've found it to not be much of a factor — at least at the performance tiers most broadband internet subscribers are using.
We hooked up a Surfboard 6141, Zoom 5345, TP-Link TC-7610 and Linksys CM-3008 to a Comcast account with Performance Pro internet service, which tops out at download speeds of 100 Mpbs. We then ran a pair of speed tests — Ookla's Speedtest.net and Comcast's own Xfinity Speedtest — from a MacBook Pro plugged directly into the cable modems using an Ethernet-to-Thunderbolt adapter. The four modems turned in download speeds ranging from 119.2 to 120.5 Mbps — really a negligible difference when assessing performance. For that reason, we gave greater weight to compatibility, design and warranty data when deciding which modem to recommend.
Arris Surfboard SB 6141: Best Cable Modem
Though it's been available for several years now, predating Arris' 2013 purchase of Motorola Home, the Surfboard SB 6141 remains the best choice for internet subscribers who've decided to buy their own modems rather than pay monthly fees to rent networking equipment. Most critically, the SB6141 is compatible with the largest internet providers, so it's likely to work with your service.
Testing the SB6141 on Comcast's Performance Pro tier, we saw average download speeds of 119.2 Mbps — a tick slower than the 120.3 Mbps averages of both the Zoom 5345 and the TP-Link TC-7610, but hardly something you're going to notice. More important, the SB6141 is a very dependable modem; I've used it in my house for the past year with no complaints. Amazon customers agree with me: More than 70 percent of the 21,000 customer reviews are 5-star ratings, with owners praising the installation and performance. If there's a persistent complaint, it's from a handful of users contending the modem stopped working after 18 months. But the modem would still be covered by the SB6141's two-year warranty.
At 5.2 x 5.2 x 1.65 inches, the all-white SB6141 tucks in neatly next to your cable box, DVR, router and any other device you happen to have nearby. You're unlikely to ever have to connect and disconnect half a dozen modems in rapid succession, but as someone who has done that, I can appreciate that the coaxial cable connector has enough distance from the power connector to make setup a breeze.
The SB6141's indicator lights are fairly visible, although in direct sunlight the green lighting the modem uses can be hard to spot. The send and receive indicators use blue lights to let you know when you've got a high-speed internet connection with bonded channels (in which the modem's channels are combined to boost throughput), or green lights when a nonbonded channel is connected — a handy at-a-glance indicator of performance.
Other DOCSIS 3.0 modems are certainly cheaper than the SB6141's current $67 price tag, though you'll still save money over renting a modem from your ISP. A Comcast subscriber paying $10 a month to rent a modem would recoup the cost of the SB6141 in eight months.
Comcast customers may be spooked by reports that the ISP was ending support for the SB6141. Although it's true that Comcast is no longer renting out this model to its subscribers, Arris says the ISP continues to provision and support SB6141 modems purchased by subscribers.
Of greater concern would be a vulnerability in some SB6141 models in which a prankster could easily cut off your internet access for a brief period. Arris has said it's working on getting a firmware fix out to ISPs. The vulnerability is more annoying than dangerous, so it doesn't affect our recommendation.
When you hook up a cable modem, you want it to work reliably and without a second thought. The Surfboard SB6141 delivers on that with the kind of indicator lights that alert you to any troubles, should they crop up.
Zoom 5345: Runner-Up
There's a lot to like about Zoom's 5345 modem, which offers a two-year warranty like the SB6141. That means your modem will continue to be under warranty for at least a year after you've paid it off with the money you saved by no longer renting equipment from your ISP. We also like that Zoom's modem is supported by Comcast and Cox, among other ISPs. A handful of Amazon user reviews note some connectivity issues with Cox and Time Warner, but generally the Zoom 5345 gets top marks for easy installation outperforming the modem supplied by the internet provider.
The 5.7 x 4.1 x 1.6-inch Zoom 5345 is a little bit more compact than the 5341J we previously looked at, and its $60 price tag should appeal to bargain hunters. While the modem's sideways-facing plug can complicate setup if you're plugging the 5345 into a power strip, we appreciate how its indicator lights can be spotted from across a room, making it easy to be aware of connectivity issues.
TP-Link TC-7610: Bargain Option
If the ultimate goal of buying your own modem is to save money, consider TP-Link's TC-7610. It can currently be had for less than $50 at Amazon, giving it one of the lowest price tags of the modems we tested. (That low price seems to be the biggest reason for the TP-7610's warm reception on Amazon, where 70 percent of the nearly 700 customer reviews give the modem 5 stars.) The TP-Link modem matched the reliability of the SB6141 and the Zoom 5345, and works with Comcast, Cox and all the ISPs that make up Charter's new empire.
The TC-7610 stands upright — it measures 5.6 x 4.5 x 2.3 inches — so don't expect to place it in a compact space. Its pinpoint-size white-and-green indicator lights may also put off some users: They're a little hard to spot; though if you don't like your networking equipment to flash like a Christmas tree, you probably won't mind. You'll get a two-year warranty with the TC-7610, so you won’t need to sacrifice coverage for that attractive price tag.
Other Modems Reviewed
We've evaluated three other 8x4 DOCSIS 3.0 modems, and the Linksys CM3008 ($48), the Netgear CM400 ($45) or the D-Link DCM-301 ($35) would be perfectly fine options for cable modems; they just have a few minor flaws that keep us from recommending them as enthusiastically as our top choices.
The CM3008 is the newest of the bunch, having just hit the market. (As such, there are no customer reviews on Amazon to act as a reference as of this writing.) Linksys' modem is certainly compact, at 4.8 x 2.76 x 0.97 inches, but when you lie it flat, it's hard to see the indicator lights to diagnose trouble. It also has just a one-year warranty.
The indicator lights are easier to spot on Netgear's CM400, but they're not labeled; instead, Netgear uses icons, which aren't ideal for an at-a-glance diagnosis of trouble. The CM400 only averages a 3.5-star rating at Amazon — low for a cable modem — with some customers citing reliability issues.
As for D-Link's DCM-301, it offers easy-to-spot indicator lights, but its coaxial cable connector is far too close to the power connector, complicating setup. Amazon customers are generally satisfied with the modem, finding it reliable and affordable, though some cited performance issues after a few months of use. Like the CM3008 and CM400, the DCM-301 offers a one-year warranty.
Best High-Speed Modems
We've concentrated on 8 x 4 modems since they're most likely to meet the needs of internet customers at the lowest price. But if you subscribe to an internet service that promises speeds greater than 150 Mbps, you'll want to get a 16 x 4 modem, which offers 16 download channels and four upload channels.
Both the SB6183 from Arris ($85) and the CM500 from Netgear ($80) turned in comparable performances when we tested them on higher-speed networks last year. We prefer the SB6183, as it packs all the things we like about the SB6141 — a two-year warranty, compatibility with major ISPs and easy-to-read indicator lights — into a cable modem that can support high-performance internet service. Amazon customers agree, with more than three-quarters of 2,350-plus user reviews awarding the SB6181 a 5-star rating, thanks to its reliable performance.
Netgear's CM500 performed admirably in our tests, but its indicator lights are difficult to see and the warranty is for only one year. That said, Amazon customers who bought the CM500 are generally pleased with its setup and performance, giving the modem an average rating of 4.5 stars.
We plan to update this guide with more reviews of modems aimed at high-speed internet plans. Among the units we're testing are the Zoom 5370 ($65), a 16 x 4 modem, and the Linksys CM3024 ($80), a 24 x 8 modem.
DOCSIS 3.1: The Future of Modems
We haven't reviewed DOCSIS 3.1 modems because high-speed broadband is available in only select markets. Still, with Internet providers expanding gigabit internet, modem makers are beginning to offer DOCSIS 3.1 devices that can deliver faster networking speeds. Linksys and Netgear unveiled DOCSIS 3.1 modems at CES in January, and Arris followed suit with a model of its own this spring.
The Linksys CM3132 offers two Gigabit Ethernet ports that you can use simultaneously for up to 2Gbps of downstream throughput. Linksys also notes that the modem can also fall back to DOCSIS 3.0 speeds, positioning it as a future-proof modem you can upgrade to now so that you'll be ready once Gigabit internet reaches your home. You'll pay a premium to do so, though: At $199, the CM3132 costs nearly three times as much as the SB6141 modem. The CM3132 ships later this spring.
Netgear's CM1000 is already available for order. Like the Linksys modem, Netgear's new offering is also backward-compatible with DOCSIS 3.0 for internet users who want to upgrade early. The $179 modem has already been certified by Comcast for use with its Internet service.
Arris bills the Surfboard SB8200 as a future-facing modem, capable of handling streaming Ultra HD and high performance gaming with its 32 download and 8 upload channels. It promises twice the speed of a DOCSIS 3.0 modem — at least if your Internet service is capable of supporting that. The $199 modem also features a pair of Gigabit Ethernet ports for wired dedicated devices.
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