[4.84 lb] I broke down and tried a Comcast XB8 rental gateway. It's operating at 1200/200.


So: 200Mbps upload speed is available to me.


It appears that Comcast set the Arris modem to 1200/35.


The modem may be worth 5 star review, but it may be that Comcast won't support it properly, even though it is one of the few modems on the list for their next gen speed tier.


Caveat emptor.

[DOCSIS 3.1] Finally have full speed. Close to 1 gig with no hickups.

[DOCSIS 3.1] Very easy to install, very happy with my new Internet speed.

[Black] Used to connect to Optimum network. Install was easy, initial boot up took 10 minutes, then rock solid. Noticeably faster than Optimum’s rental modem.

[Black] Not much to it. This modem supports the highest connection rates currently available from any cable provider I'm aware of. I've seen claims how alternate products from Motorola and Netgear have fractionally better throughput, but in my experience it's all the same.

I bought two of these modems. One supports a business account connection at my church and the other for a consumer account at my home. They work well in both cases.

I really like keeping it simpe where the cable modem is not a bunch of other products too such as a router, firewall, wireless access point, and a voice gateway.

[Black] .After upgrading to Xfinity (Comcast) 1 Gig speed tier, I needed a new modem to take advantage. I originally purchased a Motorola
MB8600. While the Motorola was indeed fast (spoiler alert: faster than the Arris S33), the Motorola was hugely unstable and unreliable on Xfinity/Comcast (Google it - you'll see its a huge problem). The Motorola was either locking up or losing Internet connection about 5-10 minutes every hour or two! Egads! It was horrible. So Motorola was returned.

Enter the Arris SURFboard S33. It activated smoothly and has been rock solid for me on Xfinity/Comcast. It is also a very small modem. The box photos make it *look* large - but it is in fact only 6 x 6 x 2 thick. Quite compact and smaller than most DOCSIS 3.1 modems.

It is fast...but, if to be honest it is slower than the MB8600 I had right before this one. My plan is rated at 1000 Mbps down and 40 Mbps up. The Motorola topped out at a very impressive 1014 Mbps down and 41.6 Mbps up. The S33 topped out at 933 Mbps down and 41.7 Mbps up. I ran tests on both modems probably 30 times at all different times of days and night. The above are my best scores. The S33 is consistently about 8-9% slower download speeds compared to the MB8600. But...reliability and stability are far more important than a marginal top-end speed difference.

The only other (slight) negative is that the S33 runs a bit warmer than both my older SURFboard model and the Motorola MB8600. It's not hot per se, but does run warmer than maybe most modems. Just make sure to give it good ventilation and it should be fine.

[Black] Just wish Xfinity would give me my speeds i pay for

[Black] Excellent modem. Not sure why i was being cheap and did not upgrade before. Highly recommended if you want to experience the speed you are paying for via your ISP for INET service..

[Black] Easy to setup. Replaced my Xfinity xFi Gateway but without telephone service. Working well for the first two weeks. The only issue is my box was missing the warranty card and the quick guide.

[DOCSIS 3.1] What a great upgrade. I wasn't getting all the bandwidth with the old ARRIS modem so I got this and now I'm getting more speed than I'm paying for.