Issue with Slow Reboot When Using Level1Tech KVM (10G Edition) on ASRock X670E PG Lightning USB-C Port

KVM Model:

1.4 Display Port KVM Switch - Single Monitor - Two Computer

USB Interface (5-gigabit or 10-gigbit):

10-gigbit


Problem:

Issue with Slow Reboot When Using Level1Tech KVM (10G Edition) on ASRock X670E PG Lightning USB-C Port

This week, I became the proud owner of a Level1Tech KVM 10G Edition. While it’s been great overall, I’ve encountered some odd behavior that I wanted to share.

The Setup

  • Motherboard: ASRock X670E PG Lightning
  • USB Connection: USB 3.2 Gen2x2 Type-C port
  • Peripherals Connected to KVM:
    • Wooting keyboard (normal USB port)
    • Razer Viper 3 Pro (HID USB port on the KVM)

The Issue

When connecting the KVM to the USB-C port (USB 3.2 Gen2x2) on my motherboard:

  • The PC experiences very slow rebooting. (Note: Not slow booting, only rebooting.)
  • The system seems to hang just before the GRUB menu.
  • When it finally reaches the GRUB menu, navigation is extremely slow, though it does eventually respond.

Troubleshooting

  • Switching the KVM connection to any other USB Type-A port resolves the issue.
  • Simply unplugging the USB-C cable also resolves the problem.

Current Status

I’ve found a workaround by avoiding the USB-C port, so functionality isn’t heavily impacted. However, I’m curious if this issue is worth reporting or if others have experienced something similar.

Looking forward to hearing if anyone has insights or solutions!

I doubt this is your problem, but just throwing it out there for some additional thinking points.

Not sure about the slow rebooting, (maybe related to enumerating devices like USB audio in the KVM?) but regarding GRUB being sluggish, could it perhaps be related to the screen resolution used when outputting video over USB-C?

I find GRUB on my old Ryzen 2500U laptop defaults to outputting to its internal panel at 1920x1080 and it’s almost unusable with massive lag unless I explicitly force it to a more sensible resolution like 640x480 through the GRUB config file.

I am not using video over usb -c in this case, this specific kvm also only supports data over usb-c, the video uses normal displayport and works fine.

If it is about enumerating usb devices, would that not also happen when connected to the usb-a ports?

not specific to the KVM, I’ve seen issues with machines that have XHCI handoff and legacy support enabled in the UEFI causing this type of behavior when peripherals are connected to USB 3+ ports.

Disabling legacy support, XHCI handoff, etc. typically resolves the issue

If you disable XHCI handoff, Are you not effectively running at usb 2.0 speeds? (looking at google explanations) what is then the benefit of having usb3.0 on the kvm?