Asus SABERTOOTH X79 - Manual (Page 84)

3-22 Chapter 3: BIOS setup
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]
[Disabled] Disables the function.
[Enabled] Enables the support for USB 3.0 devices on legacy operating systems
(OS).
EHCI Hand-off [Disabled]
[Disabled] Disables the function.
[Enabled] Enables the support for operating systems without an EHCI hand-off
feature.