Drastically slower speeds on linux machines

Recently set up my home wireless, we have the 500 mbps plan and on every non-linux device (apple devices, windows computers, etc.) in the house they get those speeds fine. However any linux device gets speeds closer to 20-50 mbps. I have devices on Ubuntu, CachyOS, and Fedora and they all have the same issue. I've tried everything I could look up and haven't made any progress towards fixing the problem, any idea what could be causing this? I have the XB7 gateway and I'm using it alone.

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EG

Expert

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121.4K Messages

23 days ago

See if this applies;

https://forums.xfinity.com/conversations/your-home-network/slow-speed-on-linux-laptop/69feaa70c30e8c2a136c2bef?commentId=6a17563fcf86fa10122b9c83

user_1j05na

Visitor

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4 Messages

I saw this post earlier, the patch described is already apart of my current system kernel (I tried to patch it manually and it was already there), and it doesn't seem to fix the issue for me. Although the issue described in that post does seem to be superficially similar to what I've been experiencing.

23 days ago

EG

Expert

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121.4K Messages

23 days ago

Sorry that it didn't work for you. Perhaps someone with an idea will come along. Good luck !

XfinityDilary

Official Employee

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3.8K Messages

22 days ago

user_1j05na Thanks for all the details. The fact that Windows, macOS, and other devices are achieving close to the expected 500 Mbps speeds while multiple Linux distributions are consistently seeing slower speeds does suggest the issue may be specific to how those devices are communicating with the WiFi network rather than the internet service itself. A few things I'd recommend checking:

Does the issue occur on both 2.4 GHz and 5 GHz connections?

Are the Linux devices connecting to WiFi 6 (802.11ax), or are they falling back to an older wireless standard?

If possible, test one of the Linux devices with a direct Ethernet connection to see if speeds improve.

Check whether any VPN, firewall, or power-saving settings are enabled on the affected devices.

Confirm that the wireless network adapters are using the latest available drivers and firmware for the Linux distribution you're running.

If all of your Linux devices are experiencing the same behavior, the adapter chipset may help narrow down the cause. Let us know the results of those tests, and we'll be happy to take a closer look with you.

XfinityDemitrius

Official Employee

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3K Messages

Thank you very much for the information @user_1j05na. I am glad to hear that all your other devices are receiving the subscribed speeds and is limited to your Linux devices only. As the subscribed speed is being delivered, we would need to refer you to Linux support for additional troubleshooting as this is outside our demarcation. We do also recommend visiting any forums boards for Linux where there community may also be able to provide support.

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21 days ago

user_zwe4nj

21 Messages

@user_1j05na Try a test. If your Ubuntu or Fedora PCs have ethernet ports. Connect a CAT5/6 cable to it and the gateway. Look at the Network > Wired parameters. See if 1,000 Mb/s is displayed. Then go to your test site to check the speed. If you're getting the ≥ 500 Mb/s, it means Linux itself is not the problem. Nor is it the gateway. I suspeect the issues are in your PC WiFi hardware. What systems are you running these Linux distros on?

Would be good to know what the output to this command is on your Linux distros.

% inxi -Nn

21 days ago

user_1j05na

Visitor

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4 Messages

I get the same reduced 50 or so Mb/s over Ethernet when connected into the gateway. The CachyOS computer is a custom built machine, the Fedora machine is a Thinkpad P14s, and the Ubuntu is an old dell laptop that probably has other problems. I will note that none of these machine have issues on another network at my old house as they were recently moved, this is specific to this xfinity setup.
Results of inxi -Nn:
CachyOS deskmargin: 0;">Device-1: Intel Wi-Fi 5 Wireless-AC 9x6x [Thunder Peak] driver: iwlwifi

Device-2: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
driver: r8169
Fedora Thinkpad:

Device 1: Intel Meteor Lake PCH CNVi WiFi driver: iwlwifi
Device 2: Intel Ethernet I219-LM driver: e1000e

(edited)

16 days ago

user_1j05na

Visitor

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4 Messages

1. Yes I get a reduced speed on both 2.4 and 5 GHz connections
2. My desktop does not support wifi 6 and uses wifi 5 on both windows and linux, the speeds still differ
3. I tried the same connection through ethernet and had the same problem, windows internet speeds were still much higher
4. I have no vpn on any of the devices, and went through a few power saving settings to fix the problem early in the process, didn't seem to make a difference.
5. I have all of my devices up to date and have updated the drivers / firmware recently

On this (desktop) computer I have an Intel Wireless-AC 9x6x [PCI ID: 8086:2526]
On my laptop it has an Intel Meteor Lake PCH CNVi WiFi [PCI ID:8086:7e40]

16 days ago

user_zwe4nj

21 Messages

Would be good to know what the output to this command is on your Linux distros.

% inxi -Nn

13 days ago

Your Home Network

user_1j05na

Drastically slower speeds on linux machines

EG

user_1j05na

EG

XfinityDilary

XfinityDemitrius

user_zwe4nj

user_1j05na

user_1j05na

user_zwe4nj

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