Thats a hardwired speedtest?
What app are you using? Or website?
What device are you testing with (computer/tablet/pc, etc)
Did you check with xfinity? Maybe there’s a line issue
3 different laptops running windows 10.
Hard wired.
Used xfinity speed test and another site I found online.
Yes, talked to xfinity - they say it’s not their fault. And the fact that I am getting way faster speeds from the old arris modem than the new one supports that.
got a screensnip of the cable connections page? Xfinity’s first response is always “its not our line”
Which cable connections page? And I am not surprised they said it’s not us, but I still find it odd that the old modem is performing so much better than the new modem.
It wouldn’t be the first time that a line was loosened while changing modems.
the connections page shows the upstream/downstream data for the modem side. Thats what we’re curious about.
Is this what you are looking for?
| Index | Frequency (Hz) | Power Level (dBmV) | SNR (dB) | Modulation | Lock Status |
|---|
| 20 | 531000000 | -8.099998 | 38.605377 | QAM256 | Locked |
| 28 | 579000000 | -8.599998 | 38.983261 | QAM256 | Locked |
| 36 | 627000000 | -9.799999 | 37.636276 | QAM256 | Locked |
| 44 | 675000000 | -10.400002 | 38.605377 | QAM256 | Locked |
| 13 | 489000000 | -6.700001 | 38.983261 | QAM256 | Locked |
| 14 | 495000000 | -9.299999 | 38.983261 | QAM256 | Locked |
| 15 | 501000000 | -7.900002 | 38.605377 | QAM256 | Locked |
| 16 | 507000000 | -7.700001 | 38.605377 | QAM256 | Locked |
| 17 | 513000000 | -9.000000 | 38.605377 | QAM256 | Locked |
| 18 | 519000000 | -7.200001 | 40.366287 | QAM256 | Locked |
| Index | FFT Type | Channel Width (dB) | # of Active Subcarriers | First Active Subcarrier (MHz) | Last Active Subcarrier (MHz) | Avg RxMER Pilot (dB) | Avg RxMER PLC (dB) | Avg RxMER Data (dB) | Power Level (dBmV) | Modulation | Lock Status |
|---|
| 193 | 4K | 192 | 3800 | 811 | 1000 | 38 | 28 | 32 | -21.4 | QAM2048 | Locked |
| Index | Frequency (Hz) | Power Level (dBmV) | Channel Type | Symbol Rate (KSym/sec) | Modulation | Lock Status |
|---|
| 18 | 22800000 | 49.520599 | US_TYPE_STDMA | 5120 KSym/sec | 64QAM | ACTIVE |
| 20 | 35600000 | 49.520599 | US_TYPE_STDMA | 5120 KSym/sec | 64QAM | ACTIVE |
| 19 | 29200000 | 48.020599 | US_TYPE_STDMA | 5120 KSym/sec | 64QAM | ACTIVE |
| 17 | 16400000 | 47.270599 | US_TYPE_STDMA | 5120 KSym/sec | 64QAM | ACTIVE |
You have mentioned the speed plan is 1GB, but this modem SBG8300 is compatible only up to 800mbps for Xfinity.
I suggest you to degrade your speed plan to fix the slow speed internet connection.
Your power levels are also out of spec. They should be fairly consistent but yours bounce around quite a bit. Plus they’re not in optimal range. I’d check your line for issues, loose connectors, kinks, corrosion, or other issues with the line
I used to get full 800 but never 900mbps with this sb3600 modem when I first got it 2 years ago on the Xfinity 1.2 gigabit plan. Every 6 months or so my speed drops and consistently stays at lower level.
I just had the Xfinity service come out and told me there was a problem with my line on outside of house and it was affecting other in area. They rewired the whole house for me (free), from the pole to the inside of my house to my modem. Before they did this I was at 400mbps now right after I cant even get 400 no matter the time I test speed. I average around 350-370mbps now.
I use “speedtest.net” and” Xfinity” own speed testing site. Never tested wifi speeds because I dont care about them. But I do transmit them for my wifi devices my kids have.
Using the same home built Windows 11 PC, 10ft of Ethernet wired into sb3600 modem. I even Installed a new network card in PC, a 2.5 gigabit PCIe adapter and no change in speed.
What am I missing to have such a significant degrade in speed?
Here is an update. I have personally restarted my modem many times in past. the Power to whole house has been off many of times over the past year. Some times for days and even once for a week(tornadoes) I’m in central IL. I have never seen any change when I personally do the modem reset.
I just called Xfinity and had them do a reset electronically and guess what. I am currently Speed testing at 960mbps. How strange is that? After all this time. I just hate calling them all you get is a run around with their automated system. I just wonder how long it will last at this speed now.
The SBG8300 is supported by Xfinity and has a speed plan of only up to 800Mbps. It looks like the speed plan that you have currently with Xfinity supports 1Gb so we suggest to degrade the speed plan to 800 Mbps and checking the hardwired speed directly connecting the device to the ethernet port of the modem without any splitters.
I used to get full 800 but never 900mbps with this sb3600 modem when I first got it 2 years ago on the Xfinity 1.2 gigabit plan. Every 6 months or so my speed drops and consistently stays at lower level.
I just had the Xfinity service come out and told me there was a problem with my line on outside of house and it was affecting other in area. They rewired the whole house for me (free), from the pole to the inside of my house to my modem. Before they did this I was at 400mbps now right after I cant even get 400 no matter the time I test speed. I average around 350-370mbps now.
I use “speedtest.net” and” Xfinity” own speed testing site. Never tested wifi speeds because I dont care about them. But I do transmit them for my wifi devices my kids have.
Using the same home built Windows 11 PC, 10ft of Ethernet wired into sb3600 modem. I even Installed a new network card in PC, a 2.5 gigabit PCIe adapter and no change in speed.
What am I missing to have such a significant degrade in speed?
Hi
Thanks for sharing you’re experience on the modem “SB3600” Please check and let us know if is this an Arris device. Thanks
The modem I’m using is the Arris SBG8300. Yes I Know now its rated at 900mbps down. But after Xfinity did a rewire from pole in alley to house I was getting less than 400 mpbs. Couple days later went though the long unnecessarily complicate automated trouble shooting by calling Xfinity. I can now get download speeds of 960mbps and upload at 42mbps. So my problem was solved not by resetting the modem my self in the home. It was solved by having Xfintiy remotely reset my connection to me.
