Slow WiFi speed on *one* PC

[PeterOz]

The user manual is crap

[PeterOz]

[HEADING=2]Troubleshoot Connectivity Affecting Individual Devices[/HEADING]
The section above focuses on solving network-level issues. If you’re having connection problems with a specific mobile device, the best way to troubleshoot is with Xfinity xFi.

Note: Alternately, if your Internet isn’t working, you can perform troubleshooting using the Xfinity My Account app.

[ol]
[li]Log in to xFi via the mobile app or website.[/li][li]Select the Connect tab.[/li][li]Select the specific device having issues.[/li][li]Scroll down and select Troubleshoot Device.[/li][li]Follow the prompts to determine what the problem may be and how to fix it.[/li][/ol]

[Myself]

[HEADING=2]Troubleshoot Connectivity Affecting Individual Devices[/HEADING]
The section above focuses on solving network-level issues. If you’re having connection problems with a specific mobile device, the best way to troubleshoot is with Xfinity xFi.

Note: Alternately, if your Internet isn’t working, you can perform troubleshooting using the Xfinity My Account app.

[ol]
[li]Log in to xFi via the mobile app or website.[/li][li]Select the Connect tab.[/li][li]Select the specific device having issues.[/li][li]Scroll down and select Troubleshoot Device.[/li][li]Follow the prompts to determine what the problem may be and how to fix it.[/li][/ol]

Hi Peter,

Sorry to sound like a broken record but I have done this exact test on numerous occasions, but sincere thanks for your time researching this point. So, when running that particular diagnostic with Xfinity it detects no problem because it is seems to be just measuring against certain performance metrics like can it browse the web, stream HD video or gaming. And of course at 112 Mbps I should be able to do all of those easily. If I report that I am still having issues it assumes the problem can be resolved by switching browsers, checking for website issues and restarting the device - all of which I have tried.

I take your point on the mesh question although I’m weighing up trying it if I can get one on a use and return if not working basis.

Yes the user manual is totally inadequate!

I’m going to do as you say and remove all other devices from the network - I might just completely disconnect these devices from WIFI as there is a “pause” option within the WIFI control app but I want to be sure of complete disconnection. I have actually done this before but it cannot harm doing it again.

Will report back…

[Myself]

Reporting back:

I disconnected every device from the network (ethernet and WIFI) and unplugged those devices I wanted to be absolutely certain were actually disconnected (2 x smart TV’s, XBOX console) to the state where the only connected device on the network was the affected PC. I verified this with the xifinity app. I ran the speed test -till got 112 Mbps. I ran it in a different browser and using different speed test services (and combinations thereof) and still got 112.

So, with everything else still disconnected I rebooted that PC. I got 450 - 460 Mbps on various test until about 3 minutes after reboot when it suddenly dropped back to 111.9 Mbps - no tapering off over time, just an immediate drop from one test to the next.

Clearly I’m a layman but it is as though there is a program that [eventually] gets running that limits the speed but I cannot see anything hogging bandwidth in the network part of the task manager (not that I know exactly what to look for anyway). Or, the modem accepts the PC onto the network and then after a few minutes says hang on you are only going to get this much bandwidth - but this doesn’t make sense to me because why would it not do the same over ethernet?

This net one is a a wild idea folks so hold onto your hats and try not to laugh too much:

The only other thing I wondered is could this PC be forming a connection somehow to another device over WIFI such that bandwidth is apportioned accordingly i.e. doubly connected or being connected to by another device (in a sinister way or otherwise).

[Rustys]

Could change the Wifi names and passwords and connect.

What you are wondering about is a possibility do not forget that there is the xfinitywifi that is available. Even that you may not have it active on your modem that does not mean that some one else in the area does.

You will need to check and see what network you are connecting to.

Goto Start
Settings
Network and Internet
On the left WiFi
On the right select Manage Known Networks
Click on every single on that are there and select Forget.

Were you ever able to access the modem directly?
If not you will need to contact xfinity to get that straightened out and or find it online.

[Myself]

Hey Rustys,

I never thought about the xfinity WIFI participation. I will disable it as I don’t require it myself anyway.

Here is what has happened today. The a new xfinity modem has arrived. I have set it up but as a completely new network - new name etc. - and during activation I chose not to import any previous settings. Initial testing is promising and I am seeing 600 ish Mbps with the usual wobbles following a first time setup.

I also did a network reset on the PC again before initializing the new modem. The affected PC was the first device to connect.

Slowly I am introducing the other devices back onto the network and testing as we go. Crunch time will be when the rabble start drifting back home later in the day to find that the “internet is down” so if I don’t make it through to tomorrow alive thanks for all your help.

But so far so good. Will report back.

[Rustys]

Thank you for keeping us informed.

[PeterOz]

The only other thing I wondered is could this PC be forming a connection somehow to another device over WIFI such that bandwidth is apportioned accordingly i.e. doubly connected or being connected to by another device (in a sinister way or otherwise).

Yes I was thinking were you connecting to another xfinity hotspot - mentions it in the manual. That’s why I suggested that you remove all devices
From the modem not just turning them off .A) you knew nothing else was an issue. B) That you would see that your pc was connected to the right network.

Thing are looking better - fingers crossed

[Myself]

Well, much disappointed to report this morning that, despite a solid and decent WIFI speed yesterday throughout the day after setting up the new modem, speeds on the problem PC have settled to a lower value - even lower than the 112 number I saw before. Now it seems I’m getting 60-80 Mbps! This is a completely new modem which I set up without any provisioning from the previous one i.e. I selected the option to setup without importing any network settings.

As with all times previously I perform the speed tests using different speed test providers and on different web browsers - all are suggesting around the same speed values.

I deliberately had not connected the second (co-located PC) to the network at this point because I wanted to rule out any possibility of interference - not that that probably makes much sense but I noticed this drop before bringing the other machine online. Now that I have brought the other PC onto the network and run speed tests the difference is startling. 70 Mbps ish on the problem PC, 580 Mbps on the other PC.

So the new modem has not only failed to help - except for several hours yesterday after initial setup - its seems to have throttled the PC even more.

Once again my conclusion is the problem must be at the way these modems apportion network bandwidth. I believe that if there was a process or processes running on the bad PC it would have shown up while on the new modem and any subsequent modem I happen install for that matter. Surely this has to be a kind or prioritization at the hub issue.

The only other thing I wondered is if the affected PC has joined the 2.4 GHz network. I only setup the new modem with a single network SSID (the default option) so it it is not split into 2.4 and 5 as was the case before.

** Yes I can see from network settings that it is on the 2.4 GHz channel.**

[Rustys]

Personally do not think that it is the modem.

This is a new one so it wont discriminate.

All the other connected devices are working normally connected wireless.

When connected to the modem via ethernet cable speeds were normal.

Replaced the modem everything works normal for the other except the affected system.

For me that rules out the modem and not the system its self.

Seems as if there is a misconfiguration some place. Can not see that is can be that card since you stated that and every one of them are acting the same.

Purchased three different WIFI receivers (PCIe, USB).

There are a lot of things that we can try like removing the references form Device Manager and allow Windows to recreate them.
While in Device Manager make sure to go under View and select Show Hidden Device.

Run a Clean Boot which may or may not show anything.

https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd

[PeterOz]

How many network cards are showing in device manager ?
I agree with Rusty about device manager.
Make sure you only have one network connection in the machine.
After you have removed them from device manager reboot.
Make sure you have the onboard network card driver.
After reboot
[ol]
[li]Right click on the Start button then choose Search.[/li][li]In the search bar, type cmd. …[/li][li]Type netsh winsock reset into the Command Prompt window and press Enter on the keyboard to run the command.[/li][li]A message will appear saying to restart the computer to complete the reset.[/li][/ol]

[Rustys]

Do you need any further assistance?

[PeterOz]

Or would you like me to give you step by step instructions

[Myself]

Hello. Sorry for the delay in returning to the matter.

So just to recap, I received a new modem from Comcast and installed it. At the same time I performed a network reset on the problematic PC.

I have definitely seen an improvement in download speed, upload speed was never affected. I seem to be able to see, using one particular testing site, a sustained 450 - 500 Mbps as opposed to the 112 Mbps previously. Another speed test service reports around half or less of that speed which is odd as they both carried the same results in previous testing. With additional testing on other services it seems to be that I can average around 300 Mbps which is obviously a major improvement over the 112 that they ALL would report prior.

The ethernet connection was never a problem and is still fine.

The new modem is exactly the same as the previous model and is still their latest offering.

Now clearly the machine is still not seeing the speeds that other devices are getting (700+) when tested from the same location and the co-located PC still outperforms it by a good 100-200 Mbps.

So although I can’t say the case is closed the situation is better than it was by a country mile and I can realize some of that performance I pay for and need.

I am very much open to further suggestions and I am happy to try anything else but from this point on I don’t know what else to do and part of me feels I’ll just have to live with it.

I thank everyone for their time and effort. A BIG thank you guys!!

Atb

[Myself]

How many network cards are showing in device manager ?
I agree with Rusty about device manager.
Make sure you only have one network connection in the machine.
After you have removed them from device manager reboot.
Make sure you have the onboard network card driver.
After reboot
[ol]
[li]Right click on the Start button then choose Search.[/li][li]In the search bar, type cmd. …[/li][li]Type netsh winsock reset into the Command Prompt window and press Enter on the keyboard to run the command.[/li][li]A message will appear saying to restart the computer to complete the reset.[/li][/ol]