ARRIS (S34) - Cable Modem - Fast DOCSIS 3.1 Multi-Gigabit Cable Modem, for Comcast Xfinity, Cox, Spectrum & More, 2.5 Gbps Max Internet Speeds, 2 Year Warranty - (No Built-in WiFi)

I ditched my ISP’s rented modem the day I upgraded to a 1.2 Gbps plan and never looked back. The SURFboard S34 is a clean, no-nonsense DOCSIS 3.1 modem with a 2.5 Gbps Ethernet port plus a bonus 1 Gbps port for link aggregation if your router supports it. Setup took under 10 minutes (activate on Xfinity/Spectrum/Cox app or phone call), and it’s been rock-solid ever since—no random reboots, no overheating, just consistent multi-gig speeds.Pros:• Real multi-gig capability — Hits 1.4–1.8 Gbps actual download on gigabit+ plans (tested with my own speed tests)• 2.5 Gbps + 1 Gbps ports — Future-proof and perfect for bonding or separate devices• 32×8 channel bonding — Locks on strong even in crowded node areas• Cool and quiet — Stays barely warm, vents well, no loud fans• Own-your-modem savings — Paid for itself in under a year vs $14/month rental fees• Easy activation on major ISPs (Xfinity, Spectrum, Cox, Mediacom)Cons:• No built-in router/WiFi — Pure modem, so you still need your own router (most people do anyway)• Pricey upfront — Not cheap, but cheaper than renting long-term• Link aggregation needs compatible router — Not everyone can use both ports at onceIf you’re on a gigabit or faster plan and tired of rental fees or sluggish ISP gear, the S34 delivers exactly what it promises: fast, stable, multi-gig internet with zero drama. One of the best modem upgrades I’ve ever made—5 stars, no hesitation.

Good modem so far. Setting up can be a slight challenge as it wants you to use an app to set it up from your phone and use a code from your email which I did not have access to because of the new modem, did manage to get it setup with an ethernet cable and laptop. Working fine so far, speeds are good and price is not too bad.

Easy setup with Comcast and works with 2.5GB downstream and 300MB upstream package. Paired with the top end Netgear Orbi mesh system. Reliable and very fast.

This Arris cable modem, is awesome it works flawlessly with my new Xfinity fiber internet. Would highly recommend.

Amazon was excellent—fast shipping, easy return, no complaints. This review is strictly about how Xfinity and the modem itself failed to deliver.I purchased the Arris S34 after receiving an email from Xfinity stating,“Your internet equipment can’t deliver the latest speeds… Find a compatible device today.”They linked to their own compatibility list, and the Arris S34 was clearly approved for my 1Gbps plan. So I replaced my reliable Netgear CM700, expecting better performance.Instead, speeds dropped, and the modem began flapping, frequent disconnects, slower throughput, and worse performance than the older CM700 it replaced. When I contacted support, Xfinity repeatedly claimed the S34 was “not recommended,” despite it being on their own list. They offered to send me their XB8 gateway and enroll me in their “Next Gen” plan, stating, “I can upgrade you to the new Gen plan, which offers 1000 Mbps + unlimited data for just $96.05, along with a new XB8 modem. You will also receive a $10 monthly discount if you enroll in Automatic Payments and Paperless Billing using your bank account.” That’s a price hike from my current $75/month—and they wouldn’t clarify what happens after the first 12 months.I asked that the S34 be removed from their recommended list. It’s misleading to approve a device publicly, then undermine it during support to push proprietary hardware.I’m returning the S34 and replacing it with a Motorola MB8600, which is also listed as compatible. If I’m treated the same way again, I’ll be switching to AT&T Fiber, which was recently installed in my neighborhood. At least they don’t play games with modem support.If you're buying this for Xfinity, be warned: the modem underperformed, and the ISP experience was even worse.Update: After I received the Motorola MB8600, Xfinity again refused to support it—despite it being on their approved list—and pushed me toward their proprietary XB8 gateway with yet another offer for “better speeds” and “lower prices.” I declined. Meanwhile, AT&T pulled fiber directly to my home. I connected it to my TP-Link router without a hitch. No drama, no games. Just fast, stable internet