User manual

41 PCE-5125 User Manual

Chapter 3 AMI BIOS Setup

! Ratio CMOS Setting

Use this to set the ratio between CPU core clock and BCLK frequencies.

! Hardware Prefetcher

Hardware Prefetcher is a technique that fetches instructions and/or data from

memory into the CPU cache memory well before the CPU needs it, so that it can

improve the load-to-use latency. You may choose to enable or disable it.

! Adjacent Cache Line Prefetch

The Adjacent Cache-Line Prefetch mechanism, like automatic hardware

prefetch, operates without programmer intervention. When enabled through the

BIOS, two 64-byte cache lines are fetched into a 128-byte sector, regardless of

whether the additional cache line has been requested or not. You may choose to

enable or disable it.

! MPS and ACPI MADT ordering

This feature allows the user to set MADT ordering. Modern ordering is for Win-

dows XP or later OSes. Legacy ordering is for Windows 2000 or earlier OSes.

! Max CPUID Value Limit

This is disabled for Windows XP.

! Intel(R) Virtualization Technology

This feature is used to enable or disable the Intel Virtualization Technology (IVT)

extension. It allows multiple operating systems to run simultaneously on the

same system. It does this by creating virtual machines, each running its own x86

operating system.

! Execute Disable Bit Capability

This item specifies the Execute Disable Bit Feature. The settings are Enabled

and Disabled. The Optimal and Fail-Safe default setting is Enabled. If Disabled

is selected, the BIOS forces the XD feature flag to always return to 0.

! Active Processor Cores

Use this to select how many processor cores you want to activate when you are

using a dual or quad core processor.

! A20M

This is to make legacy OSs compatible with some APs.

! Intel® SpeedStep™ Tech

When set to disabled, the CPU runs at its default speed, when set to enabled,

the CPU speed is controlled by the system.

! Intel® C-State Tech

When enabled, this function reduces CPU power consumption in a system halt

state. You may choose to enable or disable it.