Chapter 7: BIOS
regulated via CPU Internal Clock modulation when the CPU temperature reaches the overheat threshold.
C1/C2 Enhanced Mode (Available when supported by the CPU)
Set to Enabled to enable Enhanced Halt State (C1) and Stop Clock State (C2) to lower CPU voltage/frequency to prevent overheat. The options are Enabled and Disabled. Note: please refer to Intel’s web site for detailed information.
Execute Disable Bit (Available when supported by the CPU)
Set to Enabled to allow the processor to classify areas in memory where an ap- plication code can execute and where it cannot, and thus preventing a worm or a virus from inserting and creating a fl ood of codes to overwhelm the processor or damage the system during an attack.
Note: this feature is available when your OS and your CPU support the Execute Disable Bit function. The options are Disabled and Enabled. (For more information regarding hardware/software support for this function, please refer to Intel's and Microsoft's web sites.)
Adjacent Cache Line Prefetch (Available when supported by the CPU)
The CPU fetches the cache line for 64 bytes if this option is set to Disabled. The CPU fetches both cache lines for 128 bytes as comprised if Enabled. The default settings are Disabled for Intel 5100 Series Processors and Enabled for 5000 Series Processors.
Hardware Prefetcher (Available when supported by the CPU)
Set to Enabled to activate the hardware components that are used in conjunction with software programs to prefetch data in order to shorten execution cycles and maximize data processing effi ciency. The options are Disabled and Enabled.
Set Maximum Ext. CPUID=3
When set to Enabled, the Maximum Extended CPUID will be set to 3. The options are Disabled and Enabled.
Direct Cache Access (Available when supported by the CPU)
Set to Enable to route inbound network IO traffi c directly into processor caches to reduce memory latency and improve network performance. The options are Disabled and Enabled.