ARRIS SURFboard S33 DOCSIS 3.1 Multi‑Gig Cable Modem | 2.5Gbps + 1Gbps Ethernet Ports | Works with Xfinity, Cox, Spectrum | For Cable Internet Plans up to 2.5Gbps | Modem Only, Router Required

I should start out by stating that I am an IT professional, and have been in the industry for 24 years. I have a family of 6, all of whom are doing school remotely in this COVID world, and I've worked from home for the better part of the last 8 years, so home Internet is my livelihood. I also have one gamer in the family who tests bandwidth and connectivity to its limits for me. We moved (in town) November of 2020, so I have been on a Netgear C7100V for the past 5 months. Which, granted was its own Wifi router (2-in-1) and had a smaller price point, AND was an older model than the Arris S33. For the last 45 or so days, while on the old Netgear, my Xfinity connection had been dropping periodically. Turns out the Netgear C7100V was recently removed from the compatibility list. I figured I better buy a new modem that was on the list before I call Comcast and complain because the first thing they're going to say to me is go buy another modem before they'll support my problem. Buddy of mine in IT had the Arris S33 Surfboard, and raved about it, so I thought I'd give it a try. And because my old Netgear was a modem/router combo, I had to purchase routers too, so for context, I should disclose that I also upgraded to an Eero 6 pro 3-pack tri-band mesh wifi6 router system too. BUT, I can say unequivocally, that I never got anywhere close to the 1Gbps speeds I was paying for with the Netgear C7100V. 600mbps, tops, which is a bandwidth limitation of that device that I lived with and dealt with because no one ever got 600mbps TO the modem over wifi anyway, so the bottleneck was before the Internet egress before anyway, and still is, and probably always will be with wifi, but I digress. But with this Arris S33 Surfboard modem, I get a consistent, all day, everyday, 900+mbps of my 1gbps service. And, so far, no drops in service either since installing the Arris (fingers crossed it's only been 3 days). But even if I do, this review is still relevant because if I continue to experience drops even after the new modem and router, pretty sure it's the service provider at that point anyway. It's smaller, easy to use, quick simple setup, and if you have the Xfinity app on your phone there's no need to even call Comcast. You don't need to be an IT pro either. It took, like 20 minutes to setup, using the included quick setup guide, and it's been "set it and forget it" ever since (again, so far). I'll come back and revise this review if that changes, but I have no complaints.

This is my second time buying the ARRIS S33 DOCSIS 3.1 multi-gigabit cable modem—because lightning apparently decided my internet setup was too good and struck down my first one like Zeus himself was having a bad day. RIP, my beloved modem, you lasted just long enough to show me what true speed feels like before being vaporized in a flash. But honestly? I’m not mad. The ARRIS S33 is a beast. It supports DOCSIS 3.1, meaning it’s ready for the next-generation high-speed cable internet—like, up to 2 Gbps downstream and 1 Gbps upstream (if your ISP and plan are playing along). It’s also backwards compatible with DOCSIS 3.0, so if your ISP hasn’t fully upgraded yet, no worries. Installation is impressively painless. Plug and play, with support for IPv4 and IPv6, and it handles channel bonding like a champ—aggregating multiple channels to maximize throughput and minimize lag. I’ve thrown all kinds of traffic at it: 4K Netflix, intense online gaming sessions, video calls where my face looks mostly presentable, and it doesn’t even break a sweat. The only caveat: lightning doesn’t play nice with electronics. So if you live somewhere prone to storms like me, consider a surge protector or UPS, unless you want to keep buying backup modems like this is a weird hobby. Bottom line: the ARRIS S33 is fast, reliable, and future-proof enough to handle whatever Comcast Xfinity throws at it. Just pray to the weather gods to keep your modem alive.

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.

Worked great for 9 months. And then it didn't. Had to start playing the unplug and restart every 4 days. Reached out to Arris since it is still under warranty. They state they wont touch it since I purchased it new on Amazon. There you go, thanks Amazon.🤔😔 Update 4/29/26 Contacted the manufacturer and told them about my issues ( super hot to the touch- 115deg, slow speeds and having to reset every 4 days). First thing tech support stated was it's still under warranty. Then they asked " was there any sparks or damage to your home due to the heat"? Im thinking, "Houston we have a problem with this" when the first thing they ask is their property damage. So, to make a long story short, they are sending me another one and they want my old one sent back. Doesn't instill much confidence in the product. I most likely will not use it. The hitron replacement seems to be working just fine.

*The modem delivers high speeds for a good price point. It does as advertised. *It is very compact and much smaller than I would have imagined. *The setup was easy. No issues. The app is not the greatest. It feels laggy most of the time, no matter the phones signal. *My main concern was the connectivity access to the internet when using "both" the 2.5 gb port & the 1 gb port at the same time. For me it was a deal breaker. I want my main work station to have a direct ethernet connection to my modem while extending the internet via a wifi router throughout my home. I currently have Xfinity and after some research I would need another IP address to gain access to both ports. My solution for me was to find a modem with a built in router. I hope more people are aware of that issue. As I am not sure other internet providers are similar to Xfinity? Yet it's information that should be shared. Lastly I cannot rate the fault of the modem if it's a service provider issue (feature). If it's an industry standard than Arris needs to advertise on their product you cannot receive service via both ports simultaneously.

I've used this modem for just under three months now. It's been fairly solid. I don't have any real complaints that would make me not recommend it. For a couple days I was only getting around 150 Mbps and couldn't figure it out for the life of me. Eventually plugged directly into the modem and did a speed test and finally got the speeds I was expecting. Turns out I didn't update my quality of service settings on my router. The router was acting as a bottleneck. Once I ran another speed test with the router and updated the QoS, I got the full bandwidth I was expecting. Pros: It's fast and as seamless as any other Arris or Motorola. I have 1 Gbps service and it's gotten very close with the various speed tests. I'm assuming that's a combination of advertised vs. actual speeds from my ISP and I don't suspect it's the modem. This should last me until the modem itself fails. Even streaming several devices simultaneously at 4K wouldn't crack 1 Gbps. Heck, even if we get 8K in the future, this thing could take several devices at once. The one benefit I see to having >1 Gbps is for file transfers if you work from home and work with massive files. Even downloading 50-100 GB files via cloud servers hasn't come close to Gbit speeds. Cons: For some reason, internal pings to the modem are now being blocked. Maybe they were always blocked but I could have sworn they weren't. That's a new one for me. This is an incredibly minor downside, but as advertised, only one ethernet port is 2.5 Gbps. Fine. I don't see how anyone in normal use cases would need more than that. This is the modem, not a router or switch. I do wish there was a way to send a reboot signal from within the network, but there are probably security or other issues with that. I think the first router I owned had that. Would be kind of useful, but barely worth mentioning. Other: It claims it has an app. I have almost zero idea why it would need one. Overall: Hopefully this is the last modem I buy. Seems likely. Would recommend. Edit: Cleaned up units.

TLDR: ARRIS S33 modem: significant speed upgrade, perfect for 1.2Gbps service, but challenging Xfinity installation. 💻🚀🔄 Upgrading to the ARRIS S33 modem was like jumping to lightspeed in my home network. Coming from a history of using ARRIS products, which have always been stellar, this move was more about staying ahead in the internet speed game. The motivation? To tap into the full potential of my 1.2Gbps service. The previous modem was a faithful servant in the realm of DOCSIS 3.0, but the S33, with its DOCSIS 3.1 technology, has taken things to the next level. It's like unleashing the full power of my internet service. On my M1 iMac, I'm now hitting an average of 950 Mbps, which is phenomenal. It's a five-star experience in terms of performance. However, it's not all smooth sailing. If you're with Xfinity, brace yourself for a bit of an odyssey. The modem itself is designed for simplicity – a plug-n-play dream. But the activation with Xfinity? That's where the plot thickens. My attempt to activate through the Xfinity app hit a wall. The app was a no-go, and the chat with Xfinity agents turned into a marathon of confusion and miscommunication. From compatibility doubts to system non-recognition, it was a series of hurdles. The escalation didn't smooth things out either. A trip to the Xfinity service center, based on agent advice, turned into a waiting game and a revelation that the service centers are just as much in the dark. Despite the assurances and escalations, the solution still felt elusive. But, in a twist worthy of a tech thriller, a call from Xfinity's tech group brought the light at the end of the tunnel. The modem was finally configured, activated, and ready to go. The ordeal? Roughly 4 hours, multiple chats, a service center visit, and a pinch of patience. In conclusion, the ARRIS S33 modem is a beast in terms of speed and reliability, a definite upgrade for anyone looking to maximize their internet service. Just be prepared for a bit of an installation saga with Xfinity – it's worth it in the end!

Product is 2/3rds the size of my old one. My crowded desk looks to have slightly more space. I like the way it looks. Cute. My old one looked a bit robot overlord scary by comparison. Its one status LED tells all. Different colors, flashing vs. blinking vs. solid all have meaning. Solid blue seems to be the desired mode and color. I downloaded the app. It didn't work. The app also asked to constantly monitor my network and send data to some other rando company, I declined and it said "ok, but let me do it just this one time." with no option to opt out. When I got an error stating the the modem was unsuccessfully connected, a phone number for my ISP (Sparklight) showed up and said to call it for help. I called and they picked the phone up about 15 minutes later and they set up my modem up the old fashioned way. The tech said that she didn't know why it tries to go through the the app since most everyone has to call anyway. She said it only works with a few devices in a few areas. They were able to see it easily and set it up quickly and then reboot it to get it going. Speeds are the same as my old modem. Overall I was disappointed with the set-up process, but shouldn't have been since it's just like every other modem for the past 20 years. It works fine. Hopefully it will solve my issue of my old modem dropping out randomly lately.