Motorola SURFboard SB6121
Score: 62/100
Netgear Nighthawk CM3000
Score: 78/100Rankings
The NETGEAR Nighthawk CM3000 is a high-performance DOCSIS 3.1 mid/high-split modem offering up to 2.5 Gbps download and 1 Gbps upload, featuring a 2.5 Gbps Ethernet port and link-aggregation on two 1 Gbps ports. It lacks built-in Wi-Fi and carries a premium price, which may be unnecessary for lower-speed plans. Best suited for tech-savvy users with multi-gigabit cable subscriptions seeking future-proof 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 | 1,000 Mbpsbest | |
1 ports | 3 portsbest | |
| ↓ lower better | 0.454 kgbest | 1.111 kg |
1 yearsbest | 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 | 1000 Mbps |
Network(1) | ||
DOCSIS Standard | DOCSIS 3.0 | 3.1 |
Ports(2) | ||
Ethernet Ports (count) (ports) | 1 ports | 3 ports |
WAN Port Type | Ethernet | Coaxial |
Build & Design(2) | ||
Weight (kg) | 0.4536 kg | 1.111 kg |
Dimensions (HxWxD) (mm) | 8.7 x 6.4 x 2.0 inches mm | 121.9x222.0x234.0 mm mm |
General(1) | ||
Provider Compatibility | Time Warner Cable, Charter, Cox, Cablevision | Comcast 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.
“"outstanding" for reliability”
Professional reviewers commend the CM3000 for its top-tier download and upload capabilities, emphasizing the 2.5 Gbps speed ceiling, low-interference DOCSIS 3.1 design, and the convenience of a 2.5 Gbps Ethernet port with link aggregation. They position it as a future-proof solution for high-speed cable plans, noting its energy-efficient chipset and compact size as additional strengths.
Everyday users consistently highlight the modem's reliable high-speed performance, often seeing real-world speeds close to the advertised 2.5 Gbps download. Reviewers appreciate its seamless integration with mesh Wi-Fi systems like Orbi and its ability to handle multiple 4K streams and large uploads without hiccups. No major complaints were recorded.
