
Motorola SURFboard SB6121
Score: 62/100
TP-Link TC-7610
Score: 61/100Rankings

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.

The TP-Link TC-7610 is a DOCSIS 3.0 cable modem offering up to 343 Mbps downstream and 143 Mbps upstream speeds. It lacks integrated Wi-Fi and advanced features, making it less suitable for power users. Best for households that already own a router and need a cost-effective modem for mid-tier cable plans.
| Attribute | ![]() | ![]() |
|---|---|---|
172 Mbps | 343 Mbpsbest | |
131.072 Mbps | 143 Mbpsbest | |
1 portsbest | 1 portsbest | |
| ↓ lower better | 0.454 kgbest | 0.544 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 | 343 Mbps |
Maximum Upload Speed (Mbps) | 131.072 Mbps | 143 Mbps |
Build & Design(3) | ||
Weight (kg) | 0.4536 kg | 0.544 kg |
Dimensions (HxWxD) (mm) | 8.7 x 6.4 x 2.0 inches mm | 73x202x228 mm mm |
Form Factor | Standard | Modem |
General(2) | ||
Provider Compatibility | Time Warner Cable, Charter, Cox, Cablevision | Xfinity, Spectrum, Cox, Charter, Time Warner Cable, Bright House Networks, Cablevision |
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.

Professional reviewers commend the TC-7610 for its cost-effective approach to eliminating modem rentals, solid 8x4 channel bonding, and broad provider compatibility. However, they note the lack of integrated Wi-Fi and advanced features makes it less appealing for power users or those seeking an all-in-one solution.
Everyday users appreciate the modem's simple setup, affordability, and reliable performance for typical streaming and gaming needs. Common complaints focus on the missing Wi-Fi, occasional ISP verification hiccups, and the speed ceiling that prevents use with gigabit-level plans.

