Raspberry Pi 4 WiFi

[JMK8]

Has anyone else noticed that the Pi 4 wireless seems to have much less range than, say, the Pi 3? My normal work area is about 6 metres from the router through one breeze-block wall. I have tinkered with various Pis (2s, and 3s) in this location without any WiFi issues but the Pi 4 intermittently hangs and occasionally drops the SSH connection. If I move it closer to the router (i.e. in the same room, 2 metres from the router) it seems fine.

Or maybe I have a bad Pi 4?

_John.

[DougieLawson]

Are you using 2.4GHz or 5GHz?
5GHz has better speed, but lower range.
2.4GHz is slower but longer range.

[JMK8]

Using 2.4GHz. It just dropped out on me a few minutes ago

[jdb]

Are you using any USB3.0 devices?

[JMK8]

Yes, I have a Verbatim 47622 128GB SSD on one of the USB3 sockets. Nothing else.

[jdb]

Does your wifi performance improve if you plug the SSD in the USB2.0 ports instead? Interference between the ISM band and USB3.0 is mutual.

[JMK8]

OK, I'll give it a try. I don't know when I will report back because the problem is intermittent and can not show for several hours sometimes.

[JMK8]

Well, since moving the SSD to a USB2 port the SSH hangs and dropping off line seem to have stopped occurring. What to do?

[JMK8]

@jdb Any further thoughts on this problem?

[trejan]

Well, since moving the SSD to a USB2 port the SSH hangs and dropping off line seem to have stopped occurring. What to do?

Try changing the cable for another one with better shielding. USB 3 causes interference in the 2.4GHz band which is right where WiFi and Bluetooth is. It isn't a Pi specific issue and affects a lot of other machines.

[no3rpi]

you can also try on AP to change 2.4G channel to last one 12 or 13.

[JMK8]

Tried 3 different cables - no change. Changing the WiFi channel is not really an option. This is very disappointing, perhaps I should raise a bug report?

[haaldemir]

I was having some problem. When i connect usb 3 drive 2.4 ghz wifi goes. Now i connect 5 ghz wifi without problem.

[jdb]

Tried 3 different cables - no change. Changing the WiFi channel is not really an option. This is very disappointing, perhaps I should raise a bug report?

It isn't a bug. If your USB3 cables are leaking RF interference, then it will cause significant degradation of 2.4GHz wifi performance. It may also be the case that the SSD itself isn't particularly good at shielding the USB3.0 data lines - in which case, an option may be to switch to a powered USB3.0 hub and plug the SSD into that, then locate the hub reasonably far away from the Pi.

[Puffergas]

Yes, a common problem that I also had. Solved by just moving my USB 3 hard drive dock. There is a report written about this issue, long before the Pi4 was around.

[JMK8]

OK, looks like I will have to live with it for now. Eventually this Pi4 will be connected to my LAN so the problem should go away.