Features:

  • Support all cable internet speed tiers, up to Gigabit (1000 Mbps) service. Separate router required for WiFi
  • DOCSIS 3.1 up to 10X faster download speeds than DOCSIS 3.0. DOCSIS 3.1 is OFDM 2x2+ DOCSIS 3.0 32x8 channel bonding. 32 downstream and 8 upstream channels for DOCSIS 3.0 connection
  • ELIMINTE MONTHLY CABLE MODEM RENTAL FEES - Up to $156 per year. Note : Refer to the PDF attached below in Technical Specification for User Manual
  • Not compatible with: Verizon, AT&T, or CenturyLink. Not compatible with bundled voice services
  • Compatible with Xfinity from Comcast, Cox, Mediacom Cable, and more. System Requirements: Microsoft Windows 7, 8, 10, Vista, XP, 2000, Mac OS, or other operating systems running a TCP/IP network. Microsoft Internet Explorer 5.0, Firefox 2.0, Safari 1.4, or Google Chrome 11.0 browsers or higher
How to get the MOST speed from your Gigabit internet (I have Xfinity)

I don't do reviews often but I want to help my geek friends save days of research and frustration that I went through to finally get the absolute most speed out of my Gigabit internet. There's some golden nuggets here that you need to know. When I first upgraded to the new gigabit here in Denver (from Xfinity), it was using their new Cable Modem/Router device (XB6-A) and I was only getting 500 Mbps download speed. It was also lagging in our house when several people were gaming and others were downloading, or even accessing intensive web-pages. (lagging = pings were going up). Since upgrading to this Netgear CM1000, upgrading my cabling, and factory resetting my router, I'm now getting the most download throughput (~941 Mbps) and the lowest pings I've EVER seen! Connection is rock solid throughout the house. SHORT ANSWER: Get this Netgear CM, upgrade your ethernet cables to Cat 6 (or Cat 5E for short distances) and then Factory Reset your router to get the most speed. You still may need a new router to reach gigabit speeds. I'm getting the most download throughput (~941 Mbps) and the lowest pings I've EVER seen! I did lots of tests comparing this cable modem to the XB6-A that Xfinity provided. Here are some big things I learned: 1) Make sure your ethernet cables going from the cable modem to the router and from the router to your PC are CAT6 or at least CAT5E (for short distances). 2) Upgrading to this Netgear CM1000 Cable Modem LOWERED my ping/latency compared to the XB6-A that Xfinity provided. I just got a 5 MS Ping to the google server here in Denver! UNHEARD OF. Most of the time it's around 8-9ms with this new cable modem. I was getting 11-14 w/ the Xfinity modem. If you're a gamer, a lower ping matters! 3) The Xfinity XB6-A modem/router combo doesn't work too well when you have your own router also connected to it. Xfinity recommends you only use their device and disconnect your router. 4) Around 941 mbps is the max download speed that modern gigabit routers/switches can do right now so don't be worried if you can't get above that. 5) Many routers can't handle gigabit download speeds, especially if you've enabled any of the features like QoS, Traffic Meter, Keyword block, etc. My Netgear Nighthawk (R7000) was only getting 400-500 mbps (using speedtest) because I had enabled some of these features. Even when I disabled these features, the speed was still low. Doing a FACTORY reset fixed it, and now I'm getting 937 - 943 mbps download speed!!! The reason these routers slow down when you enable extra features is because it disables CTF (cut through forwarding) and the router no longer uses it's faster processor. Some of the newer routers can still maintain max download speeds of 941 mbps while also allowing you to use QoS and other features. 6) There's a great website called Small Net Builder that compared routers to see which could reach 941 mbps download speed. I recommend you check that out if you need a new router. Keep in mind that this Netgear CM1000 is JUST a cable modem. It's not a router. So if you only have 1 device you want to wire into it, you're fine but if you want to have more devices, and wireless, then you'll need a router too. The Xfinity provided XB6-A is both a cable modem and a wireless router in one. I personally think it has some flaws that need to be worked out but appears to be a beefy piece of hardware. You can save yourself the $10/month rental by getting this Netgear CM1000. P.S. I do plan to upgrade my router so that I can still get 941 mbps download speed while enabling QoS. With QoS, it will set aside a portion of your bandwidth (say 20%) for high priority traffic like gaming that need low latency, and then it will limit all other connections (like large downloads) to the other 80% the connection. Keep in mind, if you enable this and run a speedtest, it will appear lower simply because it's now reserving part of your bandwidth for other devices/traffic in your home.

Great router and super easy to register with Comcast.

Great router and super easy to register with Comcast. This model is recommended by Comcast and they don't joke when they say that this router is certified for Xfinity. The router asked for my Comcast account number (you can find it on your monthly bill) and seconds later it was registered and ready to go. I was amazed that registration took less than the startup time with my old modem provided by Comcast. Also, it is DOCSIS 3.1 and 3.0 backward compatible, so it should be good for years. This is my first Netgear and after reading some horror reviews with other brands either running hot or not registering with Comcast, I purchased this one and no regrets. I was looking at CM700 as well, but apparently older models suffered from issues with Intel CPU (supposedly the same across all major modem brands), so between having 3.1 support for future upgrades and new gen CPU, I figured it's worth additional $50. Finally, $10 that I used to pay for modem rental will fund speed upgrade, so this modem will be put to use right away. Side note: I got Cisco Systems Gigabit Dual WAN VPN 14 Port Router (RV325K9NA) to pair with this modem as primary WAN Gateway and DHCP server for my home net. Between these two, I get max ISP speed across all devices under any load.

Second unit perfect, first unit defective

Update: Received a replacement and it has had no issues for over a week. On today's DOCSIS 3.0 Comcast 250 I get equivalent performance to my previous SB6183 - about 260 down and 30 up. I stream 4K HDR movies well. Anticipating gigabit service in my area soon and this will be a good entry modem for DOCSIS 3.1. Replaced a reliable SB6183 with this. Setup went well. And was provisioned by Comcast correctly. Performance on Xfinity 250 in SF Bay Area on par with SB6183. However, after a week of use the unit has lost connectivity a few times requiring a reboot which is unacceptable. I am receiving a replacement unit and will update my review once I have it up and running for a week.

The best modem you will own

Worth every penny and more, do yourself a favor and upgrade now. Don't wait and you won't be sorry. I was waiting for the release of the 3.1 to upgrade my modem and couldn't be happier. I ran speed tests during peak and non peak hours wireless and check out the speed results. This is also with at least 10 devices online and while streaming. I rarely write reviews but felt compelled to on this product.

Great future-proof modem

Just received the modem today. Working perfectly so far, and was easy to set up. The Comcast self-provisioning worked for me without a hitch, just logged into my Xfinity account and was off to the races. I can confirm that this is an unmanaged device, and passes the public IP address on to whatever is plugged into it. It has no option for DHCP on the configuration page. This is, of course, typical for cable modems. The label on the bottom of the modem states that for DOCSIS 3.0, it supports 32 downstream channels and 8 upstream channels. For DOCSIS 3.1, it supports 2 downstream channels and 2 upstream channels. With DOCSIS 3.1 compatibility, I am looking forward to not having to buy a new modem for a very long time (hopefully).

Reboots needed but with reason (Updated 3-11-17)

I went against the reviews I was reading and decided to get this modem. The modem itself is great. After doing some digging there is a firmware issue with 2.01.14 and Netgear is supposed to be updating to 2.01.15 on Cox and Comcast. I called Comcast and they said they don't have any information regarding this update as of yet. The firmware issue is what is causing the T3 and T4 timeouts. I hope they get this fixed. I was really excited to have a modem do what it was advertised to do. Update 2-15-17 I rebooted this morning and the modem received the new firmware version, 2.01.15. I have been using it for a while and the uncorrectables are at 0 and the correctables are no higher than 50 per channel. I show no errors in the log all day. I am running a Mumble server with 5 people connected so there is sufficient up/down to make it hiccup. Will update again accordingly. Update 3-11-17 I have been using the modem with the updated firmware for about a month now. No issues have come up that were like previous ones. The modem gets broadcasted maintenance windows and reboots accordingly. It doesn't get stuck in the boot up where it needs shut off and turned on again. It doesn't randomly shut off anymore. My speeds have not changed like others were saying with the update. They are still the same. I have given the modem a 5 star review for the issues being resolved.

Check with Xfinity BEFORE you buy this

Check with Xfinity BEFORE you buy this - they state that you cannot use your own modem for gig service This modem worked very well, setup was simple - plug it in connect to xfinity and done. Unfortunately although it worked XFinity refused to turn on the service. The require that you rent the modem from them and that it is installed by a technician (for $60) After ordering the service on line 7 times and it not being turned on or even getting a confirmation email - I called in (6 times) - I was told that the CM1000 wont work even though it says it on the box. Finally I went to the office to return my old modem that I was renting from them and spoke to the women in the office. She told me I could use the CM1000 and that they did have to send a tech out - but would not charge me the 60 - so I said OK Luckily she enabled the 1 gig service and when I got home and rebooted the modem it worked perfectly. 950 down and 30-40 up. Again I got a call from them that I had to use their modem. When the tech showed up he switched out the modems - with their modem I am getting about 860 down and 40-50 up It also took about an hour to setup - it had to have a bunch of firmware installed. So even though the CM1000 seems to perform better (at least for down) I will be returning it One thing to keep in mind - the one from XFinity has 4 ports and wifi built in for $11 a month - so by the time you break even on buying this the technology will have probably changed again. At some point when this modem is under $100 I'll probably order one and return the one provided by xfinity. Many people recommend having them install theirs and then returning a month later when you purchase your own.

Xfinity Employee Review

I am a employee of Comcast. I am reviewing as a consumer with arguably slight bias towards my employer. I feel I should be up front about this in my review. I can confirm this modem is on our *approved* list of modems that work with our service. I chose this modem for that reason and the fact a Docsis 3.1 modem is required for speeds above 300MBps. Otherwise, a cheaper Docsis 3.0 modem would work. I bought this modem to replace my XB6 (wireless router, provided to Gigabit customers). I have always had my own netgear router (ex8000) that supports up to 1GBps. The XB6 provided speeds up to our advertised speeds but my main issue was double NAT and port forwarding issues. I am a gamer in my free time and I often had issues connecting to my friends and/or multiplayer lobbies due to double NAT routing issues. I also had to have my XB6 run through a un-managed switch as it was disconnecting often due to poor handshaking to the WAN port on my router. Not sure if this was netgear related but the issue went away after using a switch in between my XB6 and my router. Overall, the XB6 did what I needed and provided the speeds I was paying for, but I didn't need the additional features we offer to our customers. I personally didn't need the built in Wifi or hotspot of the XB6, nor did I did any of the firewall features. The XB6 does offer in home wifi for not only consumer devices but any wireless Xfinity devices such as cable boxes (Xi5, Xi6, XH, etc). Since I do not have Xfinity home or wireless cable boxes, I was looking at getting my own modem. If you have home phone from Xfinity, you will have to opt into a separate phone modem so you do not lose phone service if you decide to get your own modem. All of these previously mention notes apply to you as well if you have the XB3 wireless gateway. I have been fully switched over to this new modem for about 2-3 weeks now. I haven't lost my connection once and have it going straight into my netgear router (ex8000) without the switch in between. I immediately got a new public IP upon switching over to the new modem. Make sure to call 1-800-COMCAST to have your modem activated. To be clear, when I call in - I call in to the same number...I don't get any special hotline to call into. Within 15mins it was added to my account and working. IF you have any of the devices I mentioned previously here....the rep will not be able to switch you over until you either return the equipment that requires our XB3/XB6. I am now able to do all my own firewall/NAT rules without any problems. I am still getting the same speeds and latency. This modem does exactly what it advertises and I have no issues to report. The modem itself does have a netgear GUI (192.168.100.1) - I believe is the IP. Simple google search pulls up what it is. Nothing to configure in the GUI itself, it basically just shows the public IP and that it is connected if everything is working. This review reflects my own personal opinion and not that of my employer. I am using this modem for my own personal home connection and I did not receive compensation of any kind for this review.

Works great with Cox Communications! Exceeds the rate I'm paying for! Stays cool to the touch!

After reading all of the firmware comments, I was slightly skeptical. Others mentioned problems maintaining connections with Cox Communications. I noticed in the more recent comments there was a firmware update that supposedly resolved the problem. When the modem came up in a lightning deal, I jumped. After contacting Cox to register the modem, it took several minutes to show as connected to the internet. They could see my modem and registered it as online, but my PC still showed connectivity issues. Just as I was about to get concerned, it performed a final reboot and came completely online. I suspect the delay was when it was updating the firmware because it cycled off several times. Once it finalized its boot sequence, it was off and running. Like others have reported, it exceeds the rate I'm paying for. I subscribe to the 150mps download speed and the results at speedtest.net were clocking me at over 165mps. I've run the test several times since then and the results remain the same. I haven't had any connectivity issues since its registration. Another note: Modem is well ventilated and has not heated up at all. Cool to the touch since day 1.

Instant jump in internet speeds!

Easy to install. Saw an instant jump in my Comcast Blast speeds. I was using the Arris 6183 which is a good modem but wanted a modem that could do Gigabyte speeds. Comcast Blast speed with the 6183 was around 165 mbps and after I switched to the CM1000 it jumped to over 220 mbps wireless! I'm also using the NETGEAR Nighthawk X6 AC3200 Tri-Band Gigabit WiFi Router (R8000) with the CM1000. They pair great together and I've yet had to reboot this modem.

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