Ajt_2735's profile

Regular Visitor

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13 Messages

Friday, October 11th, 2024 11:39 PM

New Arris S33 modem upload speed way slow

I just replaced my 2 week old Xfinity modem (last test 615mbps down, 114mbps upload) with a brand new Arris S33 modem. After setup, the S33 pulled 650mbps download but only 4.97mbps upload. The setup went smoothly and my router (Linksys EA8100 v2) has not changed. I did plug router into the 2.5G modem output, should it have been in the 1G output? Our Xfinity plan is 800 down/100 up.

The Xfinity modem was a test by the tech due to 2 years on/off internet problems. Don't like forever renting a modem from Xfinity. I speed tested Xfinity modem several times before swapping with S33 so I could compare. Does Xfinity throttle personal modems trying to make you rent theirs?

Any help would be appreciated.

Thanks.

Official Employee

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1.2K Messages

1 month ago

Hello @Ajt_2735, Thanks so much for taking a moment out of your day to leave a post on our community forum. Please check out the compatible modems list here: https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2024.09.18%20Full%20List%20of%20Compatible%20Devices.pdf You would need to have a modem from the "Next Gen Speed Tier" section for you to receive the new upload speeds. If you don't want to buy a new modem then you can swap back to the rented modem and still have access to those amazing speeds. 

Regular Visitor

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13 Messages

Thank you, my technician must not have known of a separate high speed list when he recommended the S33.

Official Employee

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1.2K Messages

@Ajt_2735, I'm glad to hear we could help. Let us know if you need anything else, we are always happy to help! 

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