RT-AC68U interference if using USB3?

[wahoowad]

I've been hanging an older Seagate USB-2 portable drive off my 68U for network backups. I feel like I read a thread here years back that suggested the unit experienced interference that impacted wifi operation if using the USB3 port. Is this still true? Maybe it's a non issue?

Thanks

 

[FTC]

Hi, in my experience the interference depends on the speed (protocol used), so if you hook a USB2 disk to a USB3 port you will basically be using USB2 protocol, so you will mostly be safe. In fact, when switching on the wifi 'reduce USB interference' switch the firmware is basically doing this, forcing USB2 protocol.
Now, if you want to transfer at USB3 speeds, then I also found that most of the problem resides in the cable and connectors shielding/contact being used. I do have 2 different cables, one of which does produce 0 interference and the other makes basically noone being able to connect to the wifi when transferring data.
My experiences are based on the USB3 ports of a RT-AC3200 so yours could be a bit different however...