
Motorola SURFboard SB6121
Score: 62/100
Netgear Nighthawk CM1200
Score: 80/100Rankings

The NETGEAR Nighthawk CM1200 is a DOCSIS 3.1 desktop modem with integrated Wi-Fi 6, four Gigabit Ethernet ports, and USB 3.0, supporting up to 2 Gbps download via link aggregation. While it provides extensive connectivity, it still relies on a separate router for advanced networking and lacks 2.5 Gbps Ethernet ports. It fits power users who need high-speed wired and wireless performance on gigabit-class plans.

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 | 2,000 Mbpsbest | |
131.072 Mbpsbest | — | |
1 ports | 4 portsbest | |
— | 1 portsbest | |
| ↓ lower better | 0.454 kgbest | 0.553 kg |
1 yearsbest | 1 yearsbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Performance(1) | ||
Maximum Download Speed (Mbps) | 172 Mbps | 2000 Mbps |
Network(1) | ||
DOCSIS Standard | DOCSIS 3.0 | 3.1 |
Ports(2) | ||
Ethernet Ports (count) (ports) | 1 ports | 4 ports |
WAN Port Type | Ethernet | Coaxial |
Build & Design(3) | ||
Weight (kg) | 0.4536 kg | 0.553 kg |
Dimensions (HxWxD) (mm) | 8.7 x 6.4 x 2.0 inches mm | 10.3x3.4x6.1 inches mm |
Form Factor | Standard | Desktop |
General(1) | ||
Provider Compatibility | Time Warner Cable, Charter, Cox, Cablevision | Xfinity, Cox, Spectrum |

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.




Retailer and editorial listings emphasize the CM1200's ability to handle the fastest cable tiers, citing its DOCSIS 3.1 chipset, four Ethernet ports for link aggregation, and advanced OFDMA/QoS features as strong points for power users and gamers. The consensus is that it offers a solid, future-ready solution for households upgrading to multi-gigabit plans, though reviewers remind buyers that a separate Wi-Fi router is still required.