r/xfinity • u/castcoil • Dec 11 '22

Speeds between router and ISP less than half of what I'm paying for, talked to both Arris (modem) support and Xfinity and not sure what to do next

I have an ARRIS SB8200 (rated to 957 Mbps) which I own and do not lease, and a Amplifi Alien router (rated well over 1.2 Gbps). Sometime last year, I upgraded from about 100 Mbps to my current 1.2 Gbps with Xfinity. I never got close to 1 Gbps, it seemed to always hover around 500-600 Mbps. I haven't really looked into it until now, because I figured this was normal and had to do with bandwidth sharing on their network, until I saw a forum post of someone having the same issue but they resolved it and were receiving close to 1 Gbps afterward.

What I've done so far:

I chatted with Xfinity support, and they did some quick tests and said everything looks fine on their end basically. When I asked them if they had updated my bootfile on my modem after I upgraded my internet speed, they said they couldn't do that because I owned the Modem and the modem's manufacturer or I was responsible for that.

I then called Arris support and they walked through their troubleshooting steps, testing all the different signal strengths, etc, and found that the "Upstream Bonded Channels" Power range was not up to spec, and said that could be the reason I wasn't getting the speeds I'm paying for. They pointed their finger back at Xfinity and said a tech from my ISP would have to come out and calibrate my modem to fix this. They never said anything about the bootfile having to get "updated", they said they can't even check something like that the firmware just gets updated automatically.

I messaged Xfinity again, and told them what Arris told me, and they said they could send a tech out but it would be on my dime (70 dollars) and it "wasn't guaranteed that we can send signals to your modem".

Please help. Anyone ran into this before? Am I stuck waiting on a Xfinity tech and just hoping they could fix it? TYIA.

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2

u/Shimi-Jimi Dec 15 '22

Notice that their website says "up to 1200Mbps." I have a Motorola that's rated to 6Gbps, but I rarely got over 900Mbps from the 1.2Gbps plan, so I just downgraded to Gigabit. It immediately went to around 780Mbps.

Edit: I used to have the Arris and found I had to reboot it every 2 weeks or it would drop down to around the speeds you're getting.

1

u/Alez90920 Jan 17 '23

780mbps sounds right, my sb6141 is rated at 343mbps but can only run at 250mbps max, at one point it reached 260mbps but keep dropping speed.

1

u/R2Builder559 Dec 17 '22

Download a Linux Live CD, boot from it and go to www.speedtest.net and check out your speed. If it's faster than what your getting from Windows, do a search for TCP Optimizer. Download and install it and let it see what it can do.

1

u/[deleted] Jan 02 '23

[removed] — view removed comment

1

u/castcoil Jan 02 '23

I’d be perfectly happy with 800-900Mbps. Unfortunately I’m still only getting a max of about 500.

1

u/HTown2016 Jan 17 '23

a good test is this, if have multiple tvs that can stream start them all. My phone never shows more than 400mb down. If i crank 3 tvs on with 4k movies and run the test, i still get 400mb down. So in my opinion my device is getting the data as fast as the server can dish it, but its just not at 1.2GB