Motorola SURFboard SB6121
Score: 62/100
Arris SURFboard SB8200
Score: 75/100Rankings
The ARRIS SURFboard SB8200 is a DOCSIS 3.1 cable modem delivering very high theoretical speeds and dual Gigabit Ethernet ports. It lacks built-in Wi-Fi and can run hot, with some users experiencing lag spikes and port issues. Best suited for households that already have a separate router and need a high-performance wired modem.
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 | 10,000 Mbpsbest | |
131.072 Mbps | 2,000 Mbpsbest | |
1 ports | 2 portsbest | |
| ↓ lower better | 0.454 kgbest | 0.608 kg |
1 years | 2 yearsbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | | |
|---|---|---|
Performance(2) | ||
Maximum Download Speed (Mbps) | 172 Mbps | 10000 Mbps |
Maximum Upload Speed (Mbps) | 131.072 Mbps | 2000 Mbps |
Network(1) | ||
DOCSIS Standard | DOCSIS 3.0 | DOCSIS 3.1 |
Ports(2) | ||
Ethernet Ports (count) (ports) | 1 ports | 2 ports |
WAN Port Type | Ethernet | RJ-45 |
Build & Design(3) | ||
Weight (kg) | 0.4536 kg | 0.6078 kg |
Dimensions (HxWxD) (mm) | 8.7 x 6.4 x 2.0 inches mm | 133.35x130.30x44.45 mm mm |
Form Factor | Standard | Modem |
General(2) | ||
Provider Compatibility | Time Warner Cable, Charter, Cox, Cablevision | Xfinity, Cox, Spectrum |
Warranty (years) (years) | 1 years | 2 years |
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.
Reviewers highlight the SB8200's ability to deliver true gigabit speeds on DOCSIS 3.1 networks, praising its dual Gigabit ports, solid build, and proven compatibility with Cox and Xfinity. They note the lack of built-in Wi-Fi as a trade-off and caution that real-world speeds depend on ISP provisioning, while occasional lag spikes are mentioned as a minor drawback.
Users consistently praise the modem's speed, ease of setup, compact design, and compatibility with major ISPs, but many complain about the unit running hot, occasional lag spikes, and Ethernet port failures that cause connectivity drops.
