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Linksys High Speed Cable Modem, DOCSIS 3.0 8x4


Maximize Internet speeds to your WiFi router with the Linksys 8x4 Cable Modem (CM3008). It delivers stable high-speed connectivity for existing Internet service plans up to 100 Mbps.* Your household will enjoy awesome WiFi in no time with its easy setup.

Note: Cable customers with Internet speeds of up to 300 Mbps should use the Linksys CM3024 Cable Modem.


Owning your own modem allows you to eliminate rental fees from your service provider. The Linksys CM3008 Cable Modem is certified to work with Internet service plans from major cable providers, including Comcast Xfinity, Time Warner, Cox, and Charter--providing savings up to $120 a year on modem rental fees.

How the CM3008 Cable Modem Works


Maximize the data transfer speeds of your current Internet service plan with eight download and four upload bonded channels on the CM3008 modem. These multiple bonded channels enable you to optimize media streaming and file transfers using the CM3008 by simultaneously transferring large amounts of data over many channels. The result is more effective and efficient usage of your existing cable broadband connection.

Additionally, the CM3008 has a slim, compact design that allows you to place the cable modem with your router, and maintain a clutter-free surface area.

DOCSIS 3.0 Speed Chart


Certified for DOCSIS 3.0 cable Internet standard, this powerful modem can handle high-bandwidth transfer rates over existing cable lines with speeds of up to 343 Mbps.*

Intel Inside


To achieve high-speed downstream and upstream performance, the Linksys CM3008 Cable Modem features an Intel Puma 5 chipset. Designed to be a flexible and high-performing solution, the Puma 5 chipset will facilitate cutting-edge data service offerings as technology continues to advance.


To use the Linksys CM3008 Cable Modem, simply follow this three-step process:

Step 1 Plug modem into a power source

Plug modem into a power source

Step 2 Connect modem to wall jack

Use the coaxial cable to plug modem into wall jack

Step 3 Connect Ethernet cable

Connect Ethernet cable from modem to WiFi router

Technical Specs
  • Cable (DOCSIS) Standards:
    • DOCSIS 1.1 Certified
    • DOCSIS 2.0 Certified
    • DOCSIS 3.0 Certified
  • Network Standards:
    • IEEE802.3
    • IEEE802.3u
    • IEEE802.3ab
    • IPv6 support (Internet Protocol Version 6)
  • Ports:
    1x Gigabit Ethernet
  • Maximum Line Rate:
    Up to 343Mbps Download, Up to 120 Mbps Upload
  • LEDs:
    Power, DS (Downstream), US (Upstream), Status, Link
  • Buttons:
  • Power:
    12V 1A
  • Interfaces:
    Cable: F-type female 75 ohm
  • Warranty and Support:
    • 1-year limited warranty
    • 90-day complimentary assisted technical support
Package Contents
  • Linksys 8x4 DOCSIS 3.0 Cable Modem, CM3008
  • Quick Start Guide
  • CD-ROM with Documentation
  • Ethernet Cable
  • Phone Cables
  • Power Adapter
Rated 5 out of 5 by from WOW.WiFi was never like this I finally got the ok to install this new modem. The landlord was very rr\eluctant unless time warner said ok. Well, they did and he did, so I intalled it. The phone call took the longest. It was so easy. Ater a day or two, the reception and speed as well as distance, has improved so much that it so hard to remember putting up with the dead spots, constant buffering and lack of front yard use, it's unbelievable. And the money we saved on rental of the modem I got 50 mb SPEED INCREASE FOR NO EXTRA.. Needless to say, a great modem. I am so happy I would pY DOUBLE WITH NO COMPLAINTS. yHE FACT IT WAS FREE JUST ASTOUNDS ME.. thank you Linksys!!
Date published: 2016-08-23
Rated 5 out of 5 by from Only a cable modem!!! I used a old cable modem max 25Mbps. Now I have this Linksys's modem, Setup was easy, just called Comcast. Within half hours, everything runs. I used the sppedtest.net. I got 69.15Mbps download and upload was 6.18Mbps. Not bad at all from old to new, I am very happy about this product and will continue buying Linksys products. Just wish the ping can be lower, still not bad at all.
Date published: 2016-06-13
Rated 4 out of 5 by from Linksys CM3008 Docsis 3.0 Cable modem I received this free evaluation cable modem for the purposes of installing and using. I installed the modem into my existing system which is comprised of modem and wireless router. I removed the existing Docsis 3.0 modem and installed the CM3008 in it's place. I followed the instructions that came with the modem and contacted my cable provider. After a few steps the internet connection was up and running. It has only been running a week so I rated it 4 stars. If after several month it continues to run flawlessly without requiring rebbots I would it 5 stars.
Date published: 2016-06-09
Rated 1 out of 5 by from Problems Unfortunately I had problems with this unit...........it isn't compatible with my ISP...........I couldn't get it to install and even with help from different ISP techs, was unable to get it to work.........something about the "bonding"..........I wouldn't discourage anyone from getting this unit but I suggest you check with your ISP to see if it's on their "Approved" list of "compatible" modems first........if not, try at your own risk...........hate to be a naysayer but I can't put my stamp of approval on this since I was unable to test it in a positive manner
Date published: 2016-06-15
Rated 1 out of 5 by from Issue Connecting To TWC Bought my Linksys CM3008 from Walmart this weekend. Hooked everything up according to instruction page but no internet. I called TWC for activation and gave the tech support lady my MAC address. She did something on her end and I saw my modem rebooted. She then told me to to try using the internet but there is no connection. She told me she did see my modem model appeared on her end but then it disappeared. After an hour of troubleshooting with disconnecting the coaxial cables and hooking up the old Netgear CG3000 modem/router etc, the tech told me to return the Linksys CM3008 and I should get the Linksys CM3016 instead. Has TWC upgraded their network and made the CM3008 no longer compatible? Why is this model still selling if it is no longer compatible?
Date published: 2016-10-03
Rated 5 out of 5 by from Fast, easy hookup I received this Linksys CM3008 last week and found it very easy to install. I am replacing an older Motorola SB6141 that is much larger and takes up a lot of desk space. The CM3008 is very compact, with all the connectors on one end, and the status LED's easily visible along the edge. I had to call my ISP, Comcast, to have them manually add the modem's MAC and serial number to my account, but after doing that it worked just fine. Speeds are as fast as the older Motorola were according to multiple different test sites. I didn't expect anything faster, as this is a DOCSIS 3.0, not 3.1, and I'm not upgrading my service level at Comcast at the moment. The CM3008 runs comfortably warm (not hot!), and has no trouble supporting a Linksys wireless router with multiple clients streaming music and Netflix apps. I would definitely recommend this router if you're looking to quit paying the monthly rental fees from your ISP...
Date published: 2016-06-18
Rated 5 out of 5 by from Works great! My CM3008 was easy to hook up, replacing my rented Time Warner Arris cable modem at 8.95 a month. Once installed, I had to contact Time Warner in order to activate it. After which I found I was limited to 23mbs download speed but paying for 30. I solved it buy doing a restore default settings on my Linksys wireless router. After that I found my download speed at 37mbs. I can't say truthfully if my DL speed is increased though it may be. I should have tested the DL prior to installing the CM3008. All in all I'm very happy with it.
Date published: 2016-07-12
Rated 5 out of 5 by from Linksys Cable Modem It was easy to install. After opening web browser I was prompted to enter my Time Warner account information: zip code and telephone number or account number. Download / upload speeds were a bit unstable in the beginning -- don't know if it was a network problem or a continuing modem setup process. I have been using it for a week now without any issues.
Date published: 2016-06-12
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*343 Mbps based on DOCSIS 3.0 throughput. Maximum speed varies depending on the service provided by the cable operator. IPv6 availability is dependent upon your ISP or service provider providing IPv6 capability.
†100/300 Mbps represent the maximum throughput you can achieve with your Internet plan provided by your cable service provider. Actual throughput will be lower than 100/300 Mbps, as this throughput is dependent on your contract with your cable service provider.