The Best Cable Modems: 5 Compared (and One to Skip)

RBE top pick

ARRIS SURFboard S34

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The ARRIS SURFboard S34 is the default buy: a DOCSIS 3.1 modem with a 2.5 Gbps port that ARRIS builds for next generation upload tiers, approved for Xfinity, Spectrum and Cox, with a 2 year warranty. Choose the NETGEAR Nighthawk CM3000 if you want mid-split and high-split support, which NETGEAR rates for up to 1 Gbps upload.

Renting a modem from your cable company quietly adds a recurring fee to every bill, and a good buy-it-yourself modem can pay for itself within a year or two, depending on your provider's fee. But the retail shelf is a mess of near-identical boxes, and a couple of them are quietly outdated. We checked maker spec sheets, cable-ISP approved-device lists and owner reports to sort five current cable modems into two easy buys, two it-depends picks, and one you should skip.

RBE top pick

ARRIS

ARRIS SURFboard S34

Buy it

The S33's 2.5 Gbps hardware with a switchable upstream filter for faster next generation upload tiers, plus a 2 year warranty.

Best for: Most people on a gigabit or multi-gig cable plan who want a modem ready for faster upload tiers without paying for high-split hardware.

$$ · mid-range

Why we like it

• DOCSIS 3.1 with one 2.5 Gbps and one 1 Gbps Ethernet port, rated for cable plans up to 2.5 Gbps
• Switchable upstream filter (5-42 MHz or 5-85 MHz) per the ARRIS data sheet, so it can run the faster upload tiers cable ISPs are rolling out
• On Xfinity's Next Gen speed tier list, where Xfinity rates it for up to 444 Mbps wired upload; ARRIS lists Cox and Spectrum compatibility too
• 2 year limited warranty, double NETGEAR's 1 year

Know before buying

• No built-in Wi-Fi and no voice support, so you still need your own router and cannot use it for cable phone service
• Newer than the S33, so the owner track record is shorter

Check price on Amazon Read our detailed assessment ↓

NETGEAR

NETGEAR Nighthawk CM3000

Buy it

A mid-split and high-split DOCSIS 3.1 modem with a 2.5 Gbps port the only high-split modem here, at a higher price tier.

Best for: Buyers who want high-split upstream support and are willing to pay for high-split support their ISP may switch on later.

$$$ · premium

Why we like it

• DOCSIS 3.1 with mid-split and high-split support; NETGEAR rates it for up to 2.5 Gbps download and up to 1 Gbps upload
• On Xfinity's Next Gen speed tier list, where Xfinity rates it for up to 486 Mbps wired upload
• One 2.5 Gbps port plus two 1 Gbps ports that support link aggregation with a compatible router

Know before buying

• Costs more than the S34, and high-split only pays off once your ISP offers it; NETGEAR says high-split may come in the near future
• Not compatible with cable bundled voice service, and NETGEAR's warranty is 1 year, valid only from an authorized reseller

Check price on Amazon Read our detailed assessment ↓

ARRIS

ARRIS SURFboard S33

It depends

The proven 2.5 Gbps SURFboard, still a smart, cheaper buy if your plan has no next generation upload tier.

Best for: Buyers whose plan uses ordinary upload speeds and who want the cheaper SURFboard.

$$ · mid-range

Why we like it

• Same port layout as the S34, one 2.5 Gbps and one 1 Gbps Ethernet port, rated for plans up to 2.5 Gbps
• On Xfinity's recommended-device list and approved for Cox and Spectrum per ARRIS, with a 2 year warranty
• Large owner base and a long track record of stable connections

Know before buying

• Not on Xfinity's Next Gen speed tier list, so it cannot use Xfinity's faster upload tiers
• Runs warm and needs open air around it, per owner reports

Check price on Amazon Read our detailed assessment ↓

Hitron

Hitron CODA56

It depends

A retail DOCSIS 3.1 modem with switchable mid-split upstream and a 2.5 Gbps port, but only one Ethernet jack.

Best for: Xfinity or Cox customers who only need one wired connection and find it for less than the S34.

$$ · mid-range

Why we like it

• DOCSIS 3.1 with a 2.5 Gbps Ethernet port; Hitron rates it for up to 2.5 Gbps download and up to 1 Gbps upload
• Switchable 5-42 MHz or 5-85 MHz upstream per Hitron's data sheet, and on Xfinity's Next Gen speed tier list at up to 455 Mbps wired upload
• Hitron lists approval by Xfinity, Spectrum, Cox and Sparklight, with activation through the Xfinity app

Know before buying

• Only one Ethernet port, so there is no spare jack for a second wired device
• The product page does not state the warranty; Hitron's US warranty statement says most of its products carry one year, against ARRIS's two

Check price on Amazon Read our detailed assessment ↓

We'd skip it

ARRIS

ARRIS SURFboard SB8200

Skip it

A reliable but aging DOCSIS 3.1 modem that ARRIS rates for plans up to 1 Gbps, too often priced near the faster SURFboards.

Best for: Almost nobody shopping new today; only worth it if you find it well below the price of a 2.5 Gbps modem.

$$ · mid-range

Why we like it

• Long, well-documented owner track record on DOCSIS 3.1
• ARRIS lists Cox, Spectrum and Xfinity compatibility and a 2 year warranty

Know before buying

• Two 1 Gbps ports and no 2.5 Gbps port; ARRIS rates it for plans up to 1 Gbps
• Not on Xfinity's Next Gen speed tier list, and frequently priced near the S33, which does more

See our pick instead See it at Amazon anyway Read our detailed assessment ↓

How we judged the field

We don’t run our own modem lab. Instead, we read each maker’s spec page and data sheet, the cable-ISP approved-device lists, and aggregated owner reports to judge these modems on what matters when you’re trying to ditch a rental fee. Four things drove our verdicts. First, speed headroom: does the modem’s fastest Ethernet port keep up with gigabit and multi-gig plans, and can it use the faster upload tiers cable ISPs are rolling out? Second, ISP compatibility: a technically great modem is useless if your provider won’t activate it, so approval lists carried real weight. Third, reliability and support: owner reports on drops and heat, plus the warranty each maker states. Fourth, value: whether a modem earns its price against its closest rival.

The S34 is the modem we’d hand most people. It keeps the S33’s layout, one 2.5 Gbps and one 1 Gbps Ethernet port on DOCSIS 3.1, rated for plans up to 2.5 Gbps, and adds what ARRIS calls Next Generation Upload Speed optimization. The ARRIS data sheet Cox hosts spells it out: a switchable upstream filter that runs at 5-42 MHz or 5-85 MHz, which is what lets a modem use the mid-split upload tiers cable ISPs are rolling out. Xfinity puts it on its Next Gen speed tier list at up to 444 Mbps wired upload, and ARRIS lists Cox and Spectrum too. It carries a 2 year warranty. There’s no Wi-Fi and no voice support, and because it’s newer than the S33 its owner record is shorter. For a modem you’ll keep through the next round of upload upgrades, it’s the sensible default.

The CM3000 is for the shopper who wants the most upstream room on paper, and it is the only modem here with high-split. NETGEAR builds it on mid-split and high-split DOCSIS 3.1 and rates it for up to 2.5 Gbps download and up to 1 Gbps upload. That upload figure is NETGEAR’s rating against the DOCSIS spec; on Xfinity’s Next Gen list it is certified for up to 486 Mbps wired upload, a little above the S34’s 444. It has one 2.5 Gbps Ethernet port and two 1 Gbps ports that can be aggregated with a compatible router. NETGEAR lists it as working with Xfinity, Spectrum and Cox, though not with cable bundled voice service, and notes that mid-split is offered only by some ISPs in some regions while high-split may come in the near future. The catch is price, a tier above the S34, and a 1 year warranty against SURFboard’s 2. If you want high-split ready hardware now, it’s the one to buy.

The S33 was our previous pick and it’s still a good modem: the same 2.5 Gbps plus 1 Gbps port layout as the S34, rated for plans up to 2.5 Gbps, a 2 year warranty, and a long owner record of stable connections. Xfinity even lists it as a recommended device. What it lacks is the S34’s next generation upload support: it is on Xfinity’s general compatible list but not the Next Gen speed tier list. So it depends on your plan. If your upload speeds are ordinary and your ISP hasn’t upgraded your area, the S33 does the job for less. If you have or want a faster upload tier, spend the difference on the S34. Owners say it runs warm, so give it open air.

The CODA56 is Hitron’s retail DOCSIS 3.1 modem, and on paper it lines up with the S34 for upload readiness: Hitron’s data sheet lists a switchable 5-42 MHz or 5-85 MHz upstream, Hitron rates it for up to 2.5 Gbps download and up to 1 Gbps upload, and Xfinity puts it on the Next Gen speed tier list at up to 455 Mbps wired upload. Hitron lists approval by Xfinity, Spectrum, Cox and Sparklight, with self-activation through the Xfinity app. Two facts keep it at it depends. It has a single 2.5 Gbps Ethernet port and nothing else, so there is no spare jack. And the product page doesn’t state its warranty; Hitron’s US warranty statement says most of its products carry one year, half of ARRIS’s two. If you only need one wired connection and find it for less than the S34, it’s a fair buy.

The SB8200 isn’t a bad modem. It’s a reliable DOCSIS 3.1 unit with one of the longest owner track records on this list, and ARRIS still backs it with 2 years of warranty. The reason to skip it is headroom. It has two 1 Gbps ports and no 2.5 Gbps port, ARRIS rates it for plans up to 1 Gbps, and it isn’t on Xfinity’s Next Gen speed tier list. Yet it is frequently priced near the S33, which does more for similar money. It only makes sense if you find it clearly cheaper than a 2.5 Gbps modem and are sure you’ll never move past gigabit.

ARRIS SURFboard S34 vs NETGEAR Nighthawk CM3000: which should you buy?

Both are standalone DOCSIS 3.1 modems with a 2.5 Gbps port, both are on Xfinity’s Next Gen speed tier list, and both are listed for Xfinity, Spectrum and Cox. The difference is how far upstream they go. The S34’s filter switches between 42 MHz and 85 MHz, which covers today’s mid-split tiers. The CM3000 adds high-split, which NETGEAR says ISPs may offer in the near future, and NETGEAR rates it for up to 1 Gbps upload; Xfinity’s own certification is up to 486 Mbps for the CM3000 against 444 Mbps for the S34. The S34 counters with a lower price tier and a 2 year warranty against NETGEAR’s 1. Our rule of thumb: buy the S34 unless you specifically want high-split hardware or the CM3000’s extra 1 Gbps port. On Xfinity, neither will get X-Class speeds, which Xfinity says customer-owned modems cannot currently use.

What to look for

• DOCSIS 3.1, not 3.0. It handles today’s gigabit and multi-gig plans and stays on ISP approved lists longer.
• A 2.5 Gbps Ethernet port if you have or might get a plan faster than gigabit. A 1 Gbps-only modem will bottleneck you.
• Upload tier support. If your ISP sells faster upload plans, look for a switchable upstream filter or mid-split support, and check the ISP’s own list (Xfinity calls it the Next Gen speed tier).
• Your ISP’s approved-device list. Check that your exact model is approved for your provider and your plan speed before buying.
• Warranty and ports. Makers here range from 1 to 2 years, and port counts from one jack to three.
• Ventilation. Owners report the S33 runs warm, so give a modem open air rather than burying it in a cabinet.

Our final take

Buying your own cable modem pays you back on a schedule, and the choice is simpler than the crowded shelf suggests. The ARRIS SURFboard S34 is the pick for most people: 2.5 Gbps ready, built for the faster upload tiers cable ISPs are rolling out, approved by the big three US cable providers, and covered for 2 years. Choose the NETGEAR Nighthawk CM3000 if you want high-split support, which no other modem here offers. The ARRIS SURFboard S33 remains a cheaper buy for plans without a faster upload tier, and the Hitron CODA56 suits a one-jack setup. Skip the ARRIS SURFboard SB8200 and its 1 Gbps rating. Whichever you choose, confirm it’s on your provider’s approved list first, and remember that on Xfinity, X-Class speeds still need a leased gateway.

Deciding between the top two? See our head-to-head: ARRIS SURFboard S34 vs NETGEAR Nighthawk CM3000.

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