
Motorola SURFboard SB6121
Score: 62/100
Hitron CODA56
Score: 78/100Rankings

The Hitron CODA56 is a DOCSIS 3.1 cable modem that delivers up to 2.5 Gbps downstream speeds and a 2.5 Gbps Ethernet port, making it ideal for multi-gigabit cable plans. Its lack of integrated Wi-Fi and cable-only compatibility mean an extra router is required. Best suited for power users who already have a separate wireless solution and need the highest possible wired throughput.

The Arris SB6121 is a DOCSIS 3.0 cable modem with ENERGY STAR efficiency and front-panel LEDs, delivering up to 172 Mbps downstream for mid-tier broadband. Its limited channel bonding and lack of Wi-Fi make it unsuitable for modern high-speed plans. Ideal for budget-conscious households with basic internet needs.
| Attribute | ![]() | ![]() |
|---|---|---|
172 Mbps | 2,500 Mbpsbest | |
131.072 Mbps | 320 Mbpsbest | |
1 portsbest | 1 portsbest | |
| ↓ lower better | — | 8.92 Wbest |
| ↓ lower better | 0.454 kgbest | 0.462 kg |
1 yearsbest | — |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Performance(2) | ||
Maximum Download Speed (Mbps) | 172 Mbps | 2500 Mbps |
Maximum Upload Speed (Mbps) | 131.072 Mbps | 320 Mbps |
Network(1) | ||
DOCSIS Standard | DOCSIS 3.0 | 3.1 |
Build & Design(2) | ||
Weight (kg) | 0.4536 kg | 0.462 kg |
Dimensions (HxWxD) (mm) | 8.7 x 6.4 x 2.0 inches mm | 8.13x1.77x7.0 inches mm |
General(1) | ||
Provider Compatibility | Time Warner Cable, Charter, Cox, Cablevision | Comcast XFINITY, Comcast XFINITY Business, Charter Spectrum, Cox Gigablast, Zito Media, Astound, Grande, RCN, Wave |


Products in the top-left offer the best value (high score, low price).

Professional sources and manufacturer literature praise the SB6121 for its solid 4×4 DOCSIS 3.0 channel bonding, energy-efficient design, and reliable wired performance with major cable providers. However, reviewers note that the modem's DOCSIS 3.0 platform and limited channel count are insufficient for today's high-speed plans, and they recommend upgrading to a DOCSIS 3.1 model for future-proofing.
Typical users find the SB6121 easy to install and reliable for basic internet needs, especially when paired with a separate router for Wi-Fi. Common complaints revolve around its inability to keep up with faster broadband packages, the absence of built-in wireless, and concerns over refurbished units.

Everyday users appreciate the modem's ability to deliver the full speed of their multi-gigabit cable plans, especially for gaming and high-resolution streaming, but they are disappointed by the need to buy a separate Wi-Fi router and the restriction to cable-only service providers.

