Asus X58 A20M [Disabled], C1E Support [Enabled], CPU Ratio Setting [Auto], CPU TM function [Enabled], Active Processor Cores [All], Hardware Prefetcher [Enabled]

3 Chapter

CPU Ratio Setting [Auto]

Allows you to set the ratio between the CPU Core Clock and the BCLK Frequency. Use <+> and <-> keys to adjust the ratio. The valid value ranges vary according to your CPU model.

C1E Support [Enabled]

[Enabled]	Enables the C1E support function. This item should be enabled in order to
	enable the Enhanced Halt Sate.
[Disabled]	Disables this function.

Hardware Prefetcher [Enabled]

[Enabled]	The processor fetches data and instructions from the memory into the
	cache that are likely to be required in the near future. This reduces the
	latency associated with memory reads.
[Disabled]	Disables this function.

Adjacent Cache Line Prefetch [Enabled]

[Enabled]	The processor fetches the currently requested cache line, as well as the
	subsequent cache line. This reduces the cache latency by making the next
	cache line immediately available if the processor requires it as well.
[Disabled]	The processor fetches only the currently requested cache line.

Intel(R) Virtualization Tech [Enabled]

[Enabled]	Allows a hardware platform to run multiple operating systems separately
	and simultaneously, enabling one system to virtually function as several
	systems.
[Disabled]	Disables this function.

CPU TM function [Enabled]

[Enabled]	Enables the overheated CPU to throttle its clock speed to cool down.
[Disabled]	Disables this function.

Execute Disable Bit [Enabled]

[Enabled]	Enables the No-Execution Page Protection Technology.
[Disabled]	Forces the XD feature flag to always return to zero (0).

Intel(R) HT Technology [Enabled]

The Intel Hyper-Threading Technology allows a hyper-threading processor to appear as two logical processors to the operating system, allowing the operating system to schedule two threads or processes simultaneously.

[Enabled]	Two threads per activated core are enabled.
[Disabled]	Only one thread per activated core is enabled.

Active Processor Cores [All]

Allows you to choose the number of CPU cores to activate in each processor package. Configuration options: [All] [1] [2]

A20M [Disabled]

[Enabled]	Allows Legacy OSes to be compatible with APs.
[Disabled]	Disables this function.

3-20 Chapter 3: BIOS setup