IBM NeXtScale System Planning And Implementation Manual page 192

C-States (Default: Enable)
This option enables dynamic processor frequency and voltage changes in the
idle state, which provides potentially better power savings.
Package ACPI C-State Limit
Sets the higher C-state limit. A higher C-state limit allows the CPU to use less
power when they are idle.
C1 Enhanced Mode (Default: Enable)
This option enables processor cores to enter an enhanced halt state to lower
the voltage requirement, and it provides better power savings.
Hyper-Threading (Default: Enable)
This option enables logical multithreading in the processor so that the
operating system can run two threads simultaneously for each physical core.
Execute Disable Bit (Default: Enable)
This option enables the processor to disable the running of certain memory
areas, which prevents buffer overflow attacks.
Intel Virtualization Technology (Default: Enable)
This option enables the processor hardware acceleration feature for
virtualization.
Technology Hardware Prefetcher (Default: Enable)
This option enables the hardware prefetcher. Lightly threaded applications
and some benchmarks can benefit from having it enabled.
Adjacent Cache Prefetch (Default: Enable)
This option enables the adjacent cache line prefetch. Some applications and
benchmarks can benefit from having it enabled.
DCU Streamer Prefetcher (Default: Enable)
This option enables the stream prefetcher. Some applications and
benchmarks can benefit from having it enabled.
DCU IP Prefetcher (Default: Enable)
This option enables Instruction Pointer prefetcher. Some applications and
benchmarks can benefit from having it disabled.
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IBM NeXtScale System Planning and Implementation Guide