Customer Reviews

296
4.5 out of 5 stars
ARRIS Touchstone Cable Modem CM820 DOCSIS 3.0 8x4
Price:$63.99 + Free shipping with Amazon Prime
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104 of 110 people found the following review helpful
on February 22, 2013
Purchased this cable modem to replace my 6 year old Motorola SB5121 that I have rented from Comcrapstic the whole time. Doing the math on the total rental fees I have paid over the years yields an amount of OVER $500!!! No more rental fees. The other modem I was considering was the Mot SB6141...everyone knows about Motorola though. I chose the Arris based on the CM820A being a "3 star certified" modem per Comcrapstic's rating scale on their approved devices page. The second reason would be on the fact that Arris is a great manu of telephony/cable modems, this is mainly what they are known for.

Checking my speeds I am getting a solid and consistent 25 mbps down and 3.5 mbps up. This is phenomenal based on the fact that I am on the Performance tier. My power down is between 1.5-3 db with a 37-38 SNR on all 8 channels, awesome. My power up is 38 db, great. The interesting thing about that is that I split the signal twice before it goes to the modem, go figure. I am using PCT 2-way splitters on my setup.

***ALWAYS snug up ALL of your coax connections with a wrench***

Highly recommend the CM820A modem!!!

UPDATE 5/4/2015: Upgraded to the Blast! speed tier (rated at 50 Mbps). I am getting 60 Mbps down with a 1.2-2.0 db power reading at a 37-37.5 SNR. Pretty impressive. I am also getting 12 Mbps up at 38.25 db, very nice.

UPDATE 3/23/2015: Speeds are holding steady at 30 Mbps down and 6 Mbps up.

UPDATE 2/25/2015: The modem has been rock solid for going on two years now. No drops or connectivity issues. Very happy with the performance.

For all the people talking about not using a wrench on coax connections may have misinterpreted what I was "recommending." When I stated to "snug up all your coax connections with a wrench," I meant using a SMALL open-ended/combination wrench...not a torque wrench dialed into 150 ft lbs! If you use a small wrench and take it just past finger tight, that is all that is needed.
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32 of 35 people found the following review helpful
on June 26, 2013
I wanted to take advantage of the faster Docsis 3.0 and stop paying rental on the modem I had with Comcast. This modem arrived really fast and was easy to install. After installing it, it would not connect to the internet until I had Comcast activate it. I had to call Comcast support and tell them I replaced my modem with a new one and within a few minutes they had me going. (You need to give them the serial number and MAC address of the new modem). The lady at Comcast also took the $6 monthly rental off of my account at the same time. The modem can sit either flat like shown in the picture or on edge. It also has mounting channels in the back so it could be mounted on a wall.

I confirmed the download speed increase using speedtest.net and my speed went from around 14MB/sec before to around 24MB/sec after. I have had this modem for several weeks now and it has been working great. No problems.
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32 of 36 people found the following review helpful
on February 19, 2014
Bought this knowing this modem might not work because of the negative comments made by others, but it turned out to be working great. I called Comcast and gave them the information to activate the modem and in less than 30 min it works. I saved $8 a month from rental fees and return the rental to Comcast the same day!!!!!
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86 of 104 people found the following review helpful
on March 9, 2013
First I was switching DSL 3mb to Comcast 20mb and had a Motorola SB 6120 based on the reviews which I purchased at BB. The modem refused to lock for online no matter what I tried. So I purchased the Arris CM820 based on Comcast 3 star rating and 1PV4 & 6 compatibility. I wanted this to work as future proof for the next 5-10 years.

Unfortunately I checked Arris web site and they will only warranty their products if purchased from Cable provider or BB.

The comcast contractor who was sent out to assist with the SB6120 was unable to connet it and then we tried the Arris CM820 and while trying to get provisioning for the modem we were informed the SN was already registered with Comcast locally. They refused to provision the new modem fresh out of the sealed bag. The Comcast contractor then shared that the Arris Modems are allocated by states saying a Michigan modem would not work in Indiana. What the HE** you would figure a Cable Modem is a cable modem and you could take it anywhere you moved.

The Arris CM820 is on its way back to Amazon. I am going to see if a coworker can use the SB 6120.

Meanwhile I have an Arris WMB 760 rental...

Seems like there is a monopoly market here on modems...

Buyer beware!
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64 of 80 people found the following review helpful
on April 8, 2013
A call to Arris verified what the other reviewer said: Arris has no retail outlets. They sell their modems only to cable companies. Ostell, aModem, ElectroMax and the other sellers selling these units on Amazon are not authorized, and you may end up with a used modem.

Added later: Arris has apparently purchased Motorola's modem business. Motorola modems are sold to the public. When you see the brand name given as "Arris Motorola", you are looking at a Motorola modem. However, apparently only WHITE Motorola modems are sold to the public. The black ones are made for sale to cable companies. So even if it costs a little extra, you should buy a WHITE modem if you are getting the Arris Motorola brand.
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10 of 10 people found the following review helpful
on October 5, 2013
Replaced the same model owned by Time Warner Cable, so now I have no rental fee! This one works as well as the other.
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12 of 14 people found the following review helpful
on January 23, 2014
ARRIS is a company that acquired Motorola's modem manufacturing, and this is a great modem which is small and has a built in power supply, so it has no adapters or power bricks. It was small enough for me to install in a patch panel in my house so I never need to see it, and it's been up and running for at least 6 months now, and I haven't had to reset it once. I've hit speeds of over 70 megabits with this, and that's limited by my ISP.
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5 of 5 people found the following review helpful
on March 18, 2015
I got the modem in 2 days on prime. Called cox cable and they told me it wasn't on the approved model list and could not do anything for me. Chatted with another cox rep online and they told me I "had" to purchase the modem through them. I told him, he was full of $%^&. Called cox back and gave them the ARRIS model SB6141 which is on the approved list. Gave them the serial and mac off the modem and a couple min later I was in business. Moral of the story, tell them it is the sb141 or an arris like model on their approved list and you will be good to go. Getting the speed I pay for 50mbps.
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3 of 3 people found the following review helpful
on January 9, 2015
I got this modem after screwing around with several other models based on information I received from the comcast a website. Do not waste your time on anything from Linksys just get this model. This was the easiest hook up I've ever experienced with a modem. Worst case scenario you will have to disconnect your wireless router and reconnect it once your modem has been configured for Comcast network. All you are going to have to do for setup is to give them the serial number of your unit, the MAC address of your unit and the model number. Ten minutes later you will be flowing at incredible speeds. 5 minutes after I hooked this up I did a speed test and I was getting 49.7 megabits per second. I barely ever write reviews on this website. Please take my word for it and just get this for your Comcast high-speed Internet connection. Don't waste time with anything else, don't try to save any money just get this one.
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4 of 4 people found the following review helpful
on March 17, 2014
This modem supports IPv6, DOCIS 3.0 and has so many bonding channels the only way our internet drops connection is if our whole neighborhood goes down, it's great.
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