Chapter 3, 4 usb configuration, Legacy usb support [enabled – Asus SABERTOOTH 990FX User Manual
Page 81: Legacy usb3.0 support [enabled, Ehci hand-off [disabled

ASUS SABERTOOTH 990FX
3-19
Chapter 3
3.5.4
USB Configuration
The items in this menu allow you to change the USB-related features.
The USB Devices item shows the auto-detected values. If no USB device is detected, the
item shows None.
Legacy USB Support [Enabled]
[Disabled]
The USB devices can be used only for the BIOS setup program.
[Enabled]
Enables the support for USB devices on legacy operating systems (OS).
[Auto]
Allows the system to detect the presence of USB devices at startup. If
detected, the USB controller legacy mode is enabled. If no USB device is
detected, the legacy USB support is disabled.
Legacy USB3.0 Support [Enabled]
[Enabled]
Enables the support for USB 3.0 devices on legacy operating systems (OS).
[Disabled]
Disables the function.
EHCI Hand-off [Disabled]
[Disabled]
Disables the function.
[Enabled]
Enables the support for operating systems without an EHCI hand-off
feature.
Main
Ai Tweaker
Advanced
Monitor
Boot
Tool
Exit
Enables Legacy USB support. AUTO
option disables legacy support if no
USB devices are connected. DISABLE
option will keep USB devices
available only for EFI applications.
Back
Advanced\
USB Configuration >
UEFI BIOS Utility - Advanced Mode
USB Configuration
USB Devices:
1 Drive, 1 Mouse
Legacy USB Support
Enabled
Legacy USB3.0 Support
Enabled
EHCI Hand-off
Disabled
Mass Storage Devices:
TDK LoR Trans-It Drive PMAP
Auto
> SB USB Configuration