ARRIS Surfboard S33 DOCSIS 3.1 Multi-Gigabit Cable Modem | Approved for Comcast Xfinity, Cox, Spectrum & More | 1 & 2.5 Gbps Ports | 2.5 Gbps Max Internet Speeds | 4 OFDM Channels | 2 Year Warranty

The ARRIS SURFboard S33 is a DOCSIS 3.1 cable modem that replaces the rental unit from a cable internet provider, connecting a home network to service plans running up to 2.5 Gbps. It measures 4.74 x 1.8 x 5.14 inches, weighs 14.4 ounces, runs on 100 to 240 volts, and combines a plastic and metal build with four OFDM channels, one 1 Gbps Ethernet port and one 2.5 Gbps Ethernet port. Setup runs through the SURFboard Central app, and the modem pairs with a separate Wi-Fi router to distribute the connection. It carries approval from Xfinity, Cox, Spectrum and other major U.S. cable operators, along with a two year warranty.

This one makes sense for households on a gigabit or multi-gigabit plan who would rather buy the modem outright than keep paying a monthly rental line item, and for anyone rebuilding a home network who wants the modem and router handled as separate pieces. Confirm the model against a provider's approved device list before ordering.

When setting up the S33, place it in a spot with a few inches of clearance on all sides to let heat escape, and keep it away from enclosed cabinets or stacked electronics that can trap warmth. The unit needs to be within reach of both a coaxial cable outlet and a power source, so plan the position around those two fixed points before routing any Ethernet cable to the router. The 2.5 Gbps port is the one to connect to a router that supports multi-gig WAN input; the 1 Gbps port can serve a second wired device directly if needed.

When comparing cable modems in this category, the two things worth checking are the number of OFDM downstream channels and whether the model appears on the specific approval list for a given provider, since a modem compatible with one cable company may not be accepted by another. The S33 suits a single household rather than a multi-unit building, and it works best when paired with a router that is not a bottleneck at higher speeds. Store the original packaging and keep the warranty registration information accessible, since the two year coverage period starts from the purchase date and the unit is not user-serviceable.