Computer Hardware User Manual

Chapter 4: AMI BIOS

4-11

pendency on other timestamp calculation devices, such as an x86 RDTSC Instruc-

tion embedded in the CPU. The High Performance Event Timer is used to replace

the 8254 Programmable Interval Timer. The options are Enabled and Disabled.

Intel VT-d

Select Enabled to enable Intel's Virtualization Technology support for Direct I/O VT-d

by reporting the I/O device assignments to VMM through the DMAR ACPI Tables.

This feature offers fully-protected I/O resource-sharing across the Intel platforms,

providing the user with greater reliability, security and availability in networking and

data-sharing. The settings are Enabled and Disabled.

Intel I/OAT

The Intel I/OAT (I/O Acceleration Technology) signiﬁ cantly reduces CPU overhead

by leveraging CPU architectural improvements, freeing resources for more other

tasks. The options are Disabled and Enabled.

Active State Power Management

Select Enabled to start Active-State Power Management for signal transactions

between L0 and L1 Links on the PCI Express Bus. This maximizes power-saving

and transaction speed. The options are Enabled and Disabled.

USB Functions

This feature allows the user to decide the number of onboard USB ports to be

enabled. The Options are: Disabled, 2 USB ports, 4 USB ports, 6 USB ports, and

8 USB ports.

USB 2.0 Controller

Select Enabled to activate the onboard USB 2.0 controller. The options are En-

abled and Disabled.

Legacy USB Support

Select Enabled to use Legacy USB devices. If this item is set to Auto, Legacy USB

support will be automatically enabled if a legacy USB device is installed on the

motherboard, and vise versa. The settings are Disabled, Enabled and Auto.