Wifi stops working while doing heavy IO on USB 3

General system Kernel, boot, graphics & hardware
1

Hi, since my pc does not have an internal wifi adapter, I connected one via usb. This works great for the most part, wifi is usually stable and fast.

That is until I connect an external storage (usb stick or hard disk) to another usb 3 port and start to copy over some data (for example make a backup).

While the data is copying to the external disk, my wifi speed gets slower and slower, reaching a point after about 30 - 80 seconds I guess where it basically dropped to 0 kb/s. No packages come through, so while the system often shows I’m still connected to the wifi, I don’t have a working internet connection anymore. Sometimes the wifi even automatically disconnects. If I try to reconnect it fails.

After my data copy has finished to my external disk, things are starting getting normal again. I can reconnect to my wifi. If not, it works again after re-pluggin my wifi adapter or unmounting the external disk.

This is very frustrating because I can’t have an internet connection while I copy over some data to external USB devices.

The devices themself don’t matter. I tried different usb wifi adapters (my main one is a tp-link ac 600 (dualchannel), but same problem is with a logilink 2.4 GHz only one).

The external storage device also doesn’t matter. The problem happens when I copy data over to my external backup HDD, but also with any other usb stick. Also filesystems do not make any difference, had usb sticks with ext4, ntfs, fat32… all causing the same problem.

However USB ports do matter. At least the version. As long as everything is on an usb 3 port, the problem always occur, no matter what device is connected on which port.
But things making a difference if I connect my external storage device to a usb 2 port.
When I do this, it seems to have much less impact on wifi.
When external storage is on usb 2, my wifi connections sees some drop downs in speed, some more than usual, but I still have a working internet connection. Only when the external storage is connected to an usb 3 port the wifi completely stops working.

System Information:

inxi -Fxzc0

System:    Kernel: 5.10.16-arch1-1 x86_64 bits: 64 compiler: gcc v: 10.2.1 Desktop: KDE Plasma 5.20.5 
           Distro: EndeavourOS base: Arch Linux 
Machine:   Type: Desktop Mobo: MSI model: Z170-A PRO (MS-7971) v: 1.0 serial: <filter> UEFI: American Megatrends 
           v: 1.K0 date: 07/10/2018 
CPU:       Info: Quad Core model: Intel Core i7-7700 bits: 64 type: MT MCP arch: Kaby Lake rev: 9 
           L2 cache: 8 MiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 57616 
           Speed: 800 MHz min/max: 800/4200 MHz Core speeds (MHz): 1: 800 2: 800 3: 800 4: 800 5: 800 6: 800 
           7: 800 8: 800 
Graphics:  Device-1: NVIDIA GP106 [GeForce GTX 1060 6GB] vendor: ASUSTeK driver: nvidia v: 460.39 
           bus ID: 01:00.0 
           Display: x11 server: X.org 1.20.10 driver: loaded: nvidia unloaded: fbdev,modesetting,vesa 
           resolution: <missing: xdpyinfo> 
           OpenGL: renderer: GeForce GTX 1060 6GB/PCIe/SSE2 v: 4.6.0 NVIDIA 460.39 direct render: Yes 
Audio:     Device-1: Intel 100 Series/C230 Series Family HD Audio vendor: Micro-Star MSI driver: snd_hda_intel 
           v: kernel bus ID: 00:1f.3 
           Device-2: NVIDIA GP106 High Definition Audio vendor: ASUSTeK driver: snd_hda_intel v: kernel 
           bus ID: 01:00.1 
           Device-3: RODE Microphones RODE NT-USB type: USB driver: hid-generic,snd-usb-audio,usbhid 
           bus ID: 1-11:5 
           Sound Server: ALSA v: k5.10.16-arch1-1 
Network:   Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: Micro-Star MSI driver: r8168 
           v: 8.048.03-NAPI port: d000 bus ID: 04:00.0 
           IF: enp4s0 state: down mac: <filter> 
           Device-2: Ralink MT7610U (Archer T2U 2.4G+5G WLAN Adapter type: USB driver: mt76x0u bus ID: 1-12:18 
           IF: wlan0 state: up mac: <filter> 
Drives:    Local Storage: total: 1.19 TiB used: 583.4 GiB (47.7%) 
           ID-1: /dev/nvme0n1 vendor: Samsung model: SSD 970 EVO Plus 500GB size: 465.76 GiB temp: 28.9 C 
           ID-2: /dev/sda vendor: Samsung model: SSD 840 EVO 250GB size: 232.89 GiB 
           ID-3: /dev/sdb vendor: Samsung model: SSD 850 EVO 500GB size: 465.76 GiB 
Partition: ***
Swap:      ID-1: swap-1 type: file size: 4 GiB used: 256 KiB (0.0%) file: /swapfile 
Sensors:   System Temperatures: cpu: 34.5 C mobo: 29.8 C gpu: nvidia temp: 44 C 
           Fan Speeds (RPM): N/A gpu: nvidia fan: 0% 
Info:      Processes: 260 Uptime: 47m Memory: 31.32 GiB used: 3.13 GiB (10.0%) Init: systemd Compilers: 
           gcc: 10.2.0 Packages: 1194 Shell: Zsh v: 5.8 inxi: 3.3.00
2

This could be USB3 causing EM interference… it’s a known issue with USB3.

5 Likes
3

Thanks for the hint. So for testing I now disabled the 2,4 GHz wifi band in my routers settings. Now my pc is constantly connected via 5 GHz. (This shouldn’t interference with usb 3, right?)
Sadly the problem still persists.

Edit: Also tested using an extension cable for the wifi adapter to get more distance between the devices. It is not making anything better.

4

The driver for that card is available here. Not sure if it’s newer or not.

https://www.mediatek.com/products/broadbandWifi/mt7610u

5

The driver on that website is from 2013. I’m pretty sure the one in the linux kernel 5.10 is newer.

Also, same problems happens with another wifi adapter (rt2800usb). So not sure if this is an issue with that specific driver.

6

Just passing it on and that chip is also a usb 2 interface. I do see the date is 20130916. :+1:

7

This other possibility I can think of is that your data transfer is saturating the USB3 bus and so other devices are losing out. While the USB standard should support that level of transfer the implementation/chipset could well have issues.

2 Likes
8

Seems that was the case. I borrowed an pcie to usb card/adapter and connected my wifi adapter to it. Now the connection works even when heavy io is happening on other usb ports.
Guess I will buy a pcie wifi card soon which should fix the problem :slight_smile:

1 Like