Key Takeaways
- All three modems support DOCSIS 3.1, work with plans up to 2.5 Gbps, and have a 2.5 Gigabit Ethernet port. The differences come down to ISP approval, upload speed support, and price.
- The Hitron CODA56 is the only one of the three that supports Xfinity's faster next-gen upload tiers, and it is usually the least expensive.
- The Arris S33 is the safest pick for Spectrum customers, while the Motorola MB8611 is the low-latency favorite for gamers on Xfinity and Cox.
The Arris S33, Motorola MB8611, and Hitron CODA56 are the three most popular standalone DOCSIS 3.1 cable modems you can buy. All three eliminate your monthly rental fee, all three handle gigabit and multi-gig cable plans, and none of them include Wi-Fi, so each pairs with the router or mesh system of your choice.
Quick answer: Buy the Hitron CODA56 if you have Xfinity and want the best value plus faster uploads. Buy the Arris S33 if you have Spectrum or want the most widely approved, most proven modem. Buy the Motorola MB8611 if low latency for gaming and video calls is your top priority and your ISP still approves it.
What These Three Modems Have in Common
Before comparing differences, here is what you get with any of the three:
- DOCSIS 3.1 technology, backward compatible with DOCSIS 3.0 networks
- Support for cable internet plans up to 2.5 Gbps
- A 2.5 Gigabit Ethernet port, so a multi-gig plan is not bottlenecked at 1 Gbps
- Modem only: no built-in Wi-Fi, no phone ports, no router (a separate Wi-Fi router is required)
- Compatibility with cable internet only. None of these work with fiber, DSL, or fixed wireless service.
Comparison Table: S33 vs MB8611 vs CODA56
| Feature | Arris S33 | Motorola MB8611 | Hitron CODA56 |
|---|---|---|---|
| Max plan speed | 2.5 Gbps | 2.5 Gbps | 2.5 Gbps |
| Ethernet ports | 1x 2.5 GbE + 1x 1 GbE | 1x 2.5 GbE | 1x 2.5 GbE |
| Chipset | Broadcom BCM3390 | Broadcom | Broadcom |
| Xfinity next-gen uploads | No | No | Yes, up to roughly 400+ Mbps where available |
| Xfinity approved | Yes | Yes | Yes |
| Spectrum approved | Yes | Removed from Spectrum's current list, verify before buying | Yes |
| Cox approved | Yes | Yes | Yes |
| Standout feature | Proven reliability, second Ethernet port | Active Queue Management for low latency | Best price, fastest uploads |
| Typical price position | Highest of the three | Middle | Lowest |
Arris SURFboard S33: The Proven All-Rounder
The Arris S33 is the modern successor to the legendary SB8200 and uses the same Broadcom BCM3390 chipset, widely considered the most stable DOCSIS 3.1 silicon available. It adds a 2.5 Gigabit Ethernet port for multi-gig plans plus a secondary 1 Gigabit port. Note that the second port requires a second IP address from your provider, so most households will only use the 2.5 GbE port.
Buy the S33 if
- You have Spectrum, where the S33 remains on the approved device list
- You want the most track record and the broadest ISP support
- You may add a second internet connection or static IP later
Skip it if
- You have an Xfinity plan with next-gen upload speeds (the S33 does not support them)
- You want the lowest price
Motorola MB8611: The Low-Latency Pick
The Motorola MB8611 is the only modem in this comparison with Active Queue Management (AQM), a feature that reduces bufferbloat. In plain English, AQM keeps your connection responsive when someone in the house is downloading or streaming heavily, which means smoother online gaming and fewer frozen video calls. It has a single 2.5 Gigabit Ethernet port and a simple three-cable setup.
One important caution: Spectrum has tightened its approved device list, and the MB8611 no longer appears on it. Xfinity and Cox customers are fine, but Spectrum customers should choose the S33 or CODA56 instead.
Buy the MB8611 if
- You game online or work from home on video calls and want the lowest latency
- You have Xfinity or Cox
Skip it if
- You have Spectrum
- You need faster upload tiers on Xfinity
Hitron CODA56: The Value and Upload Champion
The Hitron CODA56 is the newest of the three and usually the least expensive, yet it is the only one that supports the faster upload speeds Xfinity has been rolling out. Where available, that means uploads of roughly 400 Mbps or more instead of the 100 to 200 Mbps ceiling of the S33 and MB8611. Tom's Guide named it the best budget cable modem, and it is certified for Xfinity, Spectrum, and Cox.
Buy the CODA56 if
- You have Xfinity and upload speed matters (cloud backups, streaming, video calls)
- You want the best price-to-performance ratio
Skip it if
- You want the longest track record: the CODA56 is newer to the US retail market than the other two
- You prefer a two-year warranty (Hitron covers the CODA56 for one year)
Which Modem Should You Buy?
- Xfinity with a fast upload tier: Hitron CODA56
- Xfinity standard gigabit: Any of the three; the CODA56 wins on price
- Spectrum: Arris S33 first, Hitron CODA56 second
- Cox: Arris S33 or Motorola MB8611
- Gamers on Xfinity or Cox: Motorola MB8611
- Multi-gig plans (1.2 to 2.5 Gbps): All three qualify; pair with a router that has a 2.5 GbE WAN port
Other Modems Worth Considering
If none of the three above fits your situation, these alternatives from our DOCSIS 3.1 modem collection cover the gaps:
- Arris SB8200: The budget standard for plans up to 1 Gbps. Same reliable chipset as the S33 without the 2.5 GbE port. [LINK]
- Arris SURFboard S34: The S33's successor, adding support for Xfinity next-gen uploads. The pick if you want Arris reliability plus fast uploads. [LINK]
- Netgear Nighthawk CM2000: A multi-gig 2.5 GbE alternative with wide ISP approval. [LINK]
- Motorola B12: Motorola's newer compact multi-gig modem, a successor option to the MB8611. [LINK]
- Hitron CODA: Hitron's 1 Gbps model for standard gigabit plans on a tighter budget. [LINK]
Every modem here still needs a Wi-Fi router to create a wireless network. If you are upgrading to a multi-gig plan, make sure your router has a 2.5 Gigabit WAN port, or the modem's extra speed goes to waste.
Frequently Asked Questions
Do the Arris S33, Motorola MB8611, and Hitron CODA56 include Wi-Fi?
No. All three are modem-only devices. You connect them to a separate Wi-Fi router or mesh system to create a wireless network. If you want an all-in-one device, look at a modem router combo like the Arris G34 or G36 instead.
Which DOCSIS 3.1 modem is best for Xfinity in 2026?
The Hitron CODA56 is the best of these three for Xfinity because it supports the faster next-gen upload tiers. For standard Xfinity gigabit plans, the Arris S33 and Motorola MB8611 also work well.
Does the Motorola MB8611 work with Spectrum?
Spectrum has removed the MB8611 from its current approved device list, so existing units may work but new activations are not guaranteed. Spectrum customers should choose the Arris S33 or Hitron CODA56 instead.
Is DOCSIS 3.1 still worth buying, or should I wait for DOCSIS 4.0?
DOCSIS 3.1 is still the standard for US cable internet in 2026. Most cable networks remain optimized for 3.1, and a quality DOCSIS 3.1 modem will stay relevant for years. Unless your provider has already deployed DOCSIS 4.0 in your area, a 3.1 modem is the practical choice.
What is the difference between a 1 GbE and a 2.5 GbE modem port?
A standard Gigabit Ethernet port caps your wired speed at 1 Gbps even if your plan is faster. A 2.5 Gigabit Ethernet port removes that ceiling, which is why all three modems in this comparison can deliver the full speed of 1.2 Gbps and 2 Gbps cable plans.
How much money does buying your own modem save?
Most major cable providers charge around 15 dollars per month for rental equipment, or roughly 180 dollars per year. Any of these three modems typically pays for itself in under a year.
Which modem is best for gaming: S33, MB8611, or CODA56?
The Motorola MB8611 has the edge for gaming thanks to Active Queue Management, which reduces latency spikes when your connection is busy. The S33 and CODA56 are also solid gaming modems since all three use modern chipsets free of the latency problems that affected older Intel Puma models.
