ARRIS(S33) - Cable Modem - Fast DOCSIS 3.1 Multi-Gigabit Cable Modem For Comcast Xfinity, Cox, Spectrum & More 1 & 2.5 Gbps Ports 2.5 Gbps Max Internet Speeds 2 Year Warranty - (No Built-in Wifi)

The ARRIS S33 modem was a great upgrade. My prior modem was another ARRIS product and it worked really well. I've had several ARRIS products and all have functioned without issue. The only reason I upgraded was because my old modem was running DOCSIS 3.0 and I wanted to move to DOCSIS 3.1 to get the most out of the 1.2Gps service that I'm paying for. This new S33 modem improved my speeds across all devices by well over 100Mbps. On my M1 iMac I'm now getting 950 Mbps on average. The ARRIS S33 modem is a five star product.I'll summarize the rest of the story so you don't have to read it if you don't want to. You CAN use this modem with your Xfinity service. But you're going to have to work to get it done. The saga below is provided so if you decide to activate this with Xfinity, you'll have an idea of what you'll go through.Now for the ugly: installing this modem with Xfinity service... This is a simple modem. It's designed to be pretty much plug-n-play. Connect coax, plug in power, plug in ethernet cable then activate through Xfinity's app. All the connections on the modem are simple. I went to Xfinity's app to activate and the activation function wouldn't work. It said I had to contact an Xfinity agent directly. So I started the chat with an Xfinity agent. I spent over an hour chatting with the agent as they tried to figure it out. First they said the modem isn't compatible with Xfinity's service. I pointed out it's the recommended modem on Xfinity's website. Then they said they couldn't find the modem in their system so couldn't register it on my account. More haggling. They escalated the issue. Escalation agent had the same problems. After more than an hour they told me I'd have to take the modem to a service center because "the service centers have special tools to scan the modem into the system directly." He assured me no appointment was necessary with my case number. Off to the Xfinity service center I go. I get there and it's a 45 minute wait. The guy says their case number doesn't mean anything to them and I'd still have to wait in line. The guy calls my name and I walk up to the counter. As soon as I lay the modem box on the counter the guy says, "Oh, no. Another one of these." He proceeds to tell me he'll do everything he can to help but they've not been able to do anything with these modems in the service center. He says the service centers don't have any special tools and have to do the same things the online agents do. And he comments that he wishes the online agents wouldn't tell customers what the service centers can do, they're always wrong and just dump problems on the service center. Sure enough, the modem isn't listed in his system either. Nice guy and admits this situation has been causing a terrible customer experience with several customers. He escalates the case to some tech group offsite. He gives me a new case number and says they will have to try to manually configure the modem for my account and I should get a call within an hour. I walked out ticked off and skeptical that I'd get a call or that they'd fix it. 50 minutes later I get a call. A nice guy from the Xfinity tech group tells me he's got it configured and it should install fine. Just have to activate it through the app. I reinstall the modem and go to the Xfinity app to activate. Same error in the app as before and it makes me contact an agent. So I start the chat and explain the situation. The chat agent says to give him a few minutes to review and attempt the activation. He comes back on about 5 minutes later and says it's activated. Sure enough. The modem light is blue and I once again have data flowing. It took somewhere about 4 hours, two chat sessions, a trip to the local service center and referral to some higher Xfinity tech group; but it finally got installed.

I bought this S33 modem in January of 2022 (today is June 26, 2025) and the thing has worked like a champ. Never did one problem occur. It was also easy peasy to set up with Xfinity. I use it exclusively wireless (I have the 1.3 gig speed from Xfinity) along with two Amplifi Alien routers (one is used as a mesh point) and I get great speeds and have around 35 wireless devices on my network (the Aliens are 1 Gb only but can speeds over that if I plug in my Macbook Air M2.But again, not one problem with the S33 and zero problems with Xfinity to get it working. I would buy a new S34 if something ever did happen to the S33 but the S33 meets all my household requirements.

Very quick and easy to install. Works perfectly. This is one of those rare devices that when it does its job, you never even notice it or think about it.

I purchased the S33 on July 25, 2023. Woke up today December 31, 2024 to find the home WiFi is down; thought it might be a Comcast outage as it usually is, but find that there is none...Looked at the S33 and found it making a high pitched whining noise with the LED constantly switching between blinking amber (Supposedly firmware download in progress?) and solid green. This went on for an hour or so, so I unplugged and replugged the power. Same thing... tried unplugging the coax as well and upon powering it on again, the LED is now stuck on solid green with a different whining sound.At this point the modem seems to be completely bricked. No internet connectivity, LED just stuck on solid green, can't access the web manager, tried different cables/power supply, even the factory reset button doesn't work. Looking online suggests that overheating may have caused this, but the modem hasn't been in a tight space or near anything else that emits heat.It is technically still under warranty, but I really don't feel like going through that whole process and having them ask me to take steps I've already tried, hard to trust the brand now anyways... it's pretty silly for a 200 dollar electronic to die in 17 months from typical use in the first place.Anyhow I needed internet to do my job, so I ran out to get a modem from another manufacturer and now everything is working fine. This modem does seem to be recommended everywhere on the internet, so perhaps I just got a defective item. Think I'll try my luck with other manufacturers after that headache though.Also just a note that the mobile app (SURFBoard Central) does not do anything for this modem, you just get to see device specs that you can literally see anywhere else. Don't bother with it.

Like a few others It took 3 days to get it to work. And now I find that only 1 of the 2 ports works at a time so redesign on my network.So History. Online since 95. Tech nerd etc.Infinity support once you get past the broke &^ english was as useless as one expects.. after a 2nd call to get them to reset my old modem and 3 harassing phone calls with them wanting to fix it before the service guy got here later. He was stuck on it for 30 min because the guy from call #1 that was useless has the wrong modem version on it... After finding out you can only use 1 or the 2 ports at a time we had to set up a switch onto my router (yes I have that much hooked up. Tech nerd remember.) Finally got everything going.They (i think) upgraded my account speed so will see if things flow any smoother. Had a arris surfboard from 2017 before and was ok. (But it you could use both ports at once.) Will see what happens from here.