Arch Linux

lepolau

Member

From: France

Registered: 2025-04-14

Posts: 5

dock's usb ports are recognized as usb 2.0 instead usb3.0 at startup

Hello everyone,
I have a problem with my usb dock.
By default, when I start my computer, the dock's usb ports are recognized as usb 2.0. As a result, read/write speeds are much slower.
If I plug in the dock once connected to my session, the ports are recognized as usb 3.0, and transfer speeds are fine.
To overcome the problem, I added “iommu=soft” to the GRUB_CMDLINE_LINUX_DEFAULT line in grub and it seems to work normally without having to connect the dock after boot.
So I've got a few questions:
what impact does this command have on my system's performance?
is this the best way of getting around the problem?