Re: 0bda:b812 USB "3.0" WLAN devices only report a maximum of 480 Mbps

[Fabian Melzow <fabian.melzow@gmail.com>]

Am Sun, 5 Nov 2023 14:16:18 -0500
schrieb Alan Stern <stern@rowland.harvard.edu>:

> On Sun, Nov 05, 2023 at 04:33:00PM +0100, Fabian Melzow wrote:
> > Am Sun, 5 Nov 2023 09:56:06 -0500
> > schrieb Alan Stern <stern@rowland.harvard.edu>:

> > > How do you know that the device's USB hardware supports more than
> > > 480 Mbps?  And even if the hardware does, maybe the firmware
> > > doesn't.
> > > 
> > > (Note: Just because the device's WLAN interface can run at 780
> > > Mbps, it does not follow that the USB interface can run that
> > > fast.)  
> > 
> > These USB WLAN sticks are sold as "USB 3.0", and also have a blue
> > USB-3.0-A-plug. I don't really know the speed, but 480 Mbps is
> > reported by "lsusb -t" or in the descriptor. I did not open these
> > devices, but have assumed that they only use a single chip to
> > handle everything, WLAN and USB.  
> 
> Have you tried plugging the device into a system running a different
> OS (Windows or MacOS-X)?  Or even a different Linux system?

Yes, I also made a short test with the lsusb of an old Debian 11
Live-DVD. I got these devices for testing from the Amazon Vine program
and after the third Monday-Hardware WLAN-device with the same problem I
thought I should report this problem, to maybe help real users.

(Forgot to send the mail also to this list.)