Product Use case Rating
Arris Surfboard SB6183 Best Cable Modem N/A
Zoom 5370 Best Value N/A
Netgear CM600 Best High-Speed Modem N/A

Best Cable Modems 2018

Relying on your internet service provider to supply you with a cable modem can cost you dearly, as many ISPs charge a monthly rental fee that adds up over time. If you’re tired of paying that tacked-on cost, get the Arris Surfboard SB6183, our top cable modem pick. The modem is compatible with a wide array of internet services, and it can handle speeds that most internet customers are getting these days. While the modem is listed for $89, you can usually find it for less. A two-year warranty on the SB6183 protects your investment.

Looking to save money? The Zoom 5370 has a lower list price than the SB6183, and it's compatible with many of the same ISPs. It also offers a two-year warranty.

Does your ISP offer speeds faster than 300 Mbps? We recommend Netgear's CM600 modem now that its price has fallen below other 32 x 8 modems (32 downstream channels and eight upstream channels). We had favored the Arris Surfboard SB6190, but it's faced user complaints over latency issues related to its Intel Puma 6 chip. The CM600's consistently lower price makes it a better option at this point.

All our recommended modems are DOCSIS 3.0 devices. Some ISPs have begun upgrading to DOCSIS 3.1, and if your internet provider is one of them, consider the DOCSIS 3.1 options we include at the end of this article. We plan on reviewing these future-proof modems as DOCSIS 3.1 becomes more widespread.

Latest Cable Modem News and Updates

If you're a Comcast customer, you may want to double-check just how fast your Internet is. In early January, the nation's largest internet provider announced that it was boosting speeds in several markets, including California, Houston, Minneapolis/St. Paul, Oregon and Colorado, among other places. The ISP's Performance Pro tier now tops out at download speeds of 150 Mbps, up from 100 Mbps, while its Blast Pro service now reaches download speeds of 250 Mbps. Comcast customers with older modems will want to make sure they have a cable modem that can take advantage of these new speeds.

What Cable Modems Cost

A 16 x 4 cable modem, which has enough speed to effectively serve most Internet subscribers, costs between $65 and $89, with most modems in that class coming in at less than $70. You'll pay more for higher-speed modems with 32 x 8 modems available for a little more than $100. DOCSIS 3.1 modems cost the most — not surprising given that they're the next generation of cable modems. You'll pay $180 to $200 for one of those modems.

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 $90 SB6183 or a $65 Zoom 5370. (And remember, that’s the list price; you can usually find that modem for less online.)

Internet Service Provider
Year 1 Cost
Year 2 Cost
Year 3 Cost
Year 4 Cost
Year 5 Cost
Total Cost Over 5 Years
Comcast Rental Fee
Cox Rental Fee
Optimum Rental Fee
Surfboard SB6183 Retail Cost
Zoom 5370 Retail Cost

Monthly rental fees for cable modems can cost you dearly each year. Comcast charges customers $10 a month if it supplies them with a cable modem; that's $120 a year on top of the internet service you also pay for. Other internet providers charge less each month, but their costs still add up over the course of a year and beyond. Buy your own modem, though, and you pay that cost just once. Just make sure to check your cable bill once you buy your own modem to make sure your ISP drops that monthly charge.

A Comcast customer who opts for the SB6183 will have covered the cost of renting a modem after nine months (and that assumes they pay full price for the modem). The savings are even more immediate with lower-priced options like the Zoom 5370 or Netgear CM500.

MORE: Opinion: I Hated Time Warner Cable, But I Came Back for Spectrum

It's more complicated for customers who get their internet service from Charter and its new Spectrum service, which includes former Time Warner Cable and Bright House customers. Spectrum internet service includes a modem as part of your subscription. (There is a $5 monthly Wi-Fi fee if you want to go wireless, so if you own both your modem and router, you can avoid that monthly Spectrum charge.) You can still use your own modem, provided it's compatible with Spectrum's service, but you won't reap savings the way Comcast subscribers can.

Monthly rental fees for cable modems can cost you dearly.

There's 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 we recommend modems with a two-year warranty.

If the speeds of your internet service tier increase, your ISP will likely upgrade your equipment for free if you’re renting. 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. And if you bundle your home telephone service with your internet, you may have to use the modem your ISP issues, so double-check with your provider.

None of this should dissuade most people from ditching their rented modem — not when you can save up to $190 after just two years of owning your own device — but those trade-offs are worth keeping in mind.

What to Look for in a Cable Modem

We base our cable modem recommendations on the four factors you should consider when shopping for a modem.

• Compatibility: The most appealing cable modem in the world won't be much good to you if your internet provider doesn't support it. Should you decide to buy your own cable modem, you should confirm with your ISP over the phone or online 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 are DOCSIS 3.0-certified by the industry R&D firm CableLabs should work with a DOCSIS-based internet service.

Modem Compatibility with Providers

Cable One
Xfinity Extreme 250/300 and lower
Speeds up to 300 Mbps
Ultimate tier and lowerSupported
Speeds up to 330 Mbps
Xfinity Extreme 250/300 and lower
Speeds up to 300 Mbps
Ultimate tier and lower
Speeds up to 330 Mbps
Zoom 5370
Xfinity Extreme 250/300 and lowerSpeeds up to 300 MbpsUltimate tier and lower
Not Listed
Not Listed
Speeds up to 330 Mbps
Xfinity Extreme 250/300 and lowerSpeeds up to 300 MbpsUltimate tier and lowerSupported
Speeds up to 330 Mbps
Xfinity Extreme 250/300 and lowerSpeeds up to 300 MbpsUltimate tier and lowerSupportedSupportedSpeeds up to 330 Mbps

• 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.

Consider whether your modem can support the speed of your internet service.

• 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.

• Speed: Consider whether your modem can support the speed of your internet service. A 16 x 4 modem is likely to support whatever your ISP throws at it, unless you happen to pay for download speeds greater than 300 Mbps. (An 8 x 4 modem will work just fine If your service is capped at 100 Mbps, though a 16 x 4 device gives you more headroom should you ever upgrade your service. We've dropped 8 x 4 modems from our list of recommended devices.)

As for performance testing, it’s really a non-issue. To confirm, we hooked up an SB6183, a Zoom 5370 and a CM500 to a Comcast account with Performance Pro internet service, which tops out at download speeds of 100 Mpbs. We then ran Ookla’s, and while the SB6183 had the fastest average, all turned in speeds over 113 Mbps. The bottom line: little distinguishes modems by performance, so pay more attention to compatibility, price, warranty and design.

Keep Your Modem and Router Separate

Some manufacturers offer modem-router hybrids — Linksys offers a $200CG7500 dual-band modem and router. While it's tempting to kill two birds with one hardware stone, keep in mind that if any part of a hybrid device 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.

MORE: Modem vs. Router: How They're Different and What They Do

Arris Surfboard SB6183: Best Cable Modem

The Arris Surfboard SB6183 is our top pick,  since it’s a dependable 16 x 4 modem that will deliver solid performance for the majority of internet users. A two-year warranty gives it an edge over Netgear’s modems, which are backed by one year of protection.

I’m a big fan of the compact design of Surfboard modems, and the SB6183 is no exception. At 5.2 x 5 x 2.1 inches, the all-white SB6183 tucks unobtrusively next to a router, cable box and whatever other hardware you have on hand. The coaxial cable connector is a little too close to the power connector for my taste, but you’re likely to only have to deal with that once.

The SB6183 favors a simple row of vertical indicator lights that are easier enough to spot, though the yellow lighting can be a little hard to see if your modem’s in direct sunlight. Still, it’s pretty easy to glance at the SB6183 and see if there’s any issue with your internet connectivity.

The SB6183 gets a largely positive response on Amazon, with more than 70 percent of 6,200-plus user reviews left a 5-star rating, thanks to its performance. (Note that Amazon appears to lump user reviews of multiple Arris products together, so pay attention to the reviews connected to the company's 16x4 modems if you're looking for feedback on the SB6183.) The negative reviews largely cite reliability issues that develop over time.

You may have heard reports of security flaws affecting Arris and Motorola broadband modems, routers and gateways supplied by AT&T to its internet customers. Those flaws do not appear to impact the Surfboard modem lineup that's sold directly to consumers, so that security warning shouldn't impact your cable modem choice.

Zoom 5370: Best Value

More internet providers list compatibility with the SB6183 than the Zoom modem, but if the 5370 is supported by your ISP, the 16 x 4 modem is a good, lower-cost alternative to Arris’ device. The Zoom 5370 is larger than the SB6183, but at 6.9 x 5.4 x 1.5 inches, it’s still relatively slender when compared with other bulkier modems. And its all-black look may fit in better with your other internet hardware.

I particularly like the 5370’s indicator lights, which are good and bright. More important, they’re clearly labeled, instead of making you rely on icons to let you know what light shows which function. A power button in the back makes resets easy, and gives you a one-press option for cutting off internet access (something parents might appreciate if their kids spend dinner glued to their devices).

Around 400 people have reviewed the Zoom 5370 at Amazon, but the reviewers are overwhelming positive. Users like the easy setup and reliable performance, and you can likely get a 5370 for less than an SB6183 while still enjoying the protection of a two-year warranty.

Netgear CM500: A Solid Choice

At $60, Netgear’s 16 x 4 modem costs less than the SB6183, and it enjoys wide compatibility with internet service providers. On the downside, Netgear offers only a one-year warranty on the CM500.

Netgear’s CM500 is taller than the SB6183 and Zoom 5370, at 7.3 inches. I also found its indicator lights difficult to see, though at night, you may appreciate the lack of a light show.  The coaxial and power connectors are also far apart on the CM500, making this an easy modem to set up.

Amazon customers who bought the CM500 are generally pleased with its setup and performance, giving the modem an average rating of 4.2 stars. Three-quarters of the 1,700 or so reviews on Amazon are of the 5-star variety.

High-Speed Modems: What You Need to Know

We’ve looked at a trio of modems that offer a little more horsepower than their 16 x 4 counterparts, but with 16 x 4 devices capable of handling up to 300 Mbps download speeds, only a sliver of internet users will need to pay for performance beyond that, and most who do should probably jump on the DOCSIS 3.1 modem train since that's what many ISPs are upgrading to.

Previously, we recommended the 32x8 SB6190 ($129, but currently available for $98 at Amazon) as the best high-speed option, thanks to its compact size (it’s roughly as big as the SB6183) and two-year warranty. But users have complained about latency attributed to the Intel Puma 6 chip that the SB6190 uses, with some even filing a class-action suit. I've used the SB6190 without issue for the past several months, though I don't do the kind of online gaming that's going to be impacted by latency issues. Arris also says that it's released a firmware update to address the issue, though ISPs deploy such updates on their own schedule.

Still, another high-speed modem
the CM600 from Netgear now costs less than the SB6190. And it doesn't have the Puma 6 chipset so there's no danger of running into the latency issues that some SB6190 users have experienced. (Perhaps that's why this Netgear modem enjoys more positive reviews on Amazon.) It only has a one-year warranty, but the 8.7 x 5.3 x 2.4-inch CM600 performed reliably when we tested it. Given the lower price tag, it's the better choice at this point.

We've also tested the CM3024 from Linksys (now $65 on Amazon) though that 8 x 7 x 1.8-inch modem uses the same Puma 6 chip that has triggered user complaints about the SB6190.

What Modems We Test: DOCSIS 3.0

We focus 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, and major internet providers have upgraded to that standard.

Our recommendations now focus on 16 x 4 modems — those are devices with 16 downstream channels and four upstream channels — since they can support internet plans that deliver download speeds up to 300 Mbps. We have looked at a trio of more powerful modems — the 24 x 8 Netgear CM600 and Linksys CM3024 as well as the 32 x 8 Arris SB6190 — but unless your internet plan offers lightning-fast speeds, these $100-plus modems are likely overkill for your needs.

DOCSIS 3.1: The Future of Modems

We haven't reviewed DOCSIS 3.1 modems because high-speed broadband is available in only some markets, and even then, some providers don't yet allow you to bring your own DOCSIS 3.1 modems. Still, with Internet providers expanding gigabit internet, modem makers are beginning to offer DOCSIS 3.1 devices that can deliver 1000 Mbps download speeds.

Check with your cable provider to see if DOCSIS 3.1 has been deployed in your area or if it's about to be. If so, consider some of the DOCSIS 3.1 options that modem makers have already announced. If DOCSIS 3.1 isn't in your immediate future, though, a DOCSIS 3.0 modem will serve your needs just fine.

Linksys and Netgear unveiled DOCSIS 3.1 modems at the start of 2017, and Arris followed suit with a model of its own in the spring. Linksys has since put the launch of its CM3132 modem on hold, but other DOCSIS 3.1 devices are now available.

Netgear's CM1000 is backward-compatible with DOCSIS 3.0 for internet users who want to upgrade early. The modem has 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 eight 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 modem also features a pair of gigabit Ethernet ports for wired dedicated devices.

Motorola's DOCS 3.1 modem also has 32 download and eight upload channels. It also features Active Queue Management for speeding up page loads and gaming. Motorola says the modem's compatible with Comcast's Xfinity service as well as high-speed internet from Cox.

Other Modems Reviewed

We’ve evaluated a bunch of 8 x 4 modems over the last two years, and because modems are basically a commodity, they remain widely available. Here’s a quick rundown of these different devices and what we thought about each one.

What We Liked
What We Didn't
Average Amazon Customer Rating
TP-Link TC-7610
$59.99Best Buy Low price; reliable performance
Hard-to-spot indicator lights
4.3 stars
Zoom 5345 $44.90Amazon Two-year warranty; visible indicator lightsMinor setup complains4.4 stars
Netgear CM400 $44.99Amazon Visible indicator lights; competitive priceUsers cite reliability issues in online reviews3.4 stars
Linskys CM3008 $50.74Amazon Compact design; easy setupIndicator lights aren’t always easy to spot; pricey compared to other 8x4 modems4.2 stars
D-Link DCM 301 $49.99Amazon Easy-to-spot indicator lights; reliableOne-year warranty; not listed as supported by some ISPs4.3 stars

Photo Credits: Philip Michaels/Tom's Guide

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  • InMesa
    Why don't they make modems with an indicator so a person knows when it needs to be replaced. Issues connecting to the internet could be the fault of the provider, router, modem, or the device that's trying to connect. It's a nightmare trying to troubleshoot where the problem is.
  • rgd1101
    Anonymous said:
    Why don't they make modems with an indicator so a person knows when it needs to be replaced. Issues connecting to the internet could be the fault of the provider, router, modem, or the device that's trying to connect. It's a nightmare trying to troubleshoot where the problem is.

    Like you said, it complicated, it will cost a lot more $ to build something that can troubleshoot itself
  • clabzor
    DO NOT USE SB6190 - Can't believe it is even being considered (much less any Puma 6 chipset)
  • seahag
    I think the graphic at the top is incorrect, it says SB1690, I think it should be SB6190.
  • shellbacksnipe
    None of this is relevant unless you tighten your coax F-connector on the wall plate and the back of the modem. If it's even slightly loose you've got ingress. Which means packet loss, slower speeds, modem resets, T3 timeouts, ect... So do yourself a favor and make sure those fittings are adequately tightened. Oh and one more thing. Don't go cheap on the coax cable. Use RG6 tri shield or better. 98% of internet trouble calls to your Cable ISP are caused by these two things.
  • coldwash
    Not what I would expect from a Best of 2018 review. Rehash of 2017 products with very little new insight. At the least focus on docsis 3.1 in more detail while updating purchase considerations for docsis 3.0. Arris modems while pushed like crazy have out of spec xmit power and can be very troublesome on a perfect gain cable signal through a top tier provider.
  • shellbacksnipe
    Anonymous said:
    Not what I would expect from a Best of 2018 review. Rehash of 2017 products with very little new insight. At the least focus on docsis 3.1 in more detail while updating purchase considerations for docsis 3.0. Arris modems while pushed like crazy have out of spec xmit power and can be very troublesome on a perfect gain cable signal through a top tier provider.

    What are you talking about? Out of spec US TX? If your Arris modem is out of spec it's not because of the device itself, it's because of crap wiring, crap splitters, crap f-connectors, or because some rocket scientist decided to connect their coaxial cable to a surge protector or UPS. Guess what? Your service drop is already bonded to your main electrical ground. It's NEC. It's mandatory. If you do that it's redundant and pointless. All you are doing is attenuating signal for no reason and causing a ton of other issues with ICFR, SNR, MER, BER, all of which impact your internet surfing/gaming/streaming abilities.
  • ek4man
    I was thinking of replacing the Comcast supplied cable router/modem. The issues we are having are constant rebooting needed (which most of these seem to take care of) and poor WiFi transmission distance. Which of these had the best WiFi coverage?