Chapter 4: BIOS
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Power Performance Tuning
This feature allows the user to set whether the operating system or the BIOS controls
the Energy Performance BIAS (EPB). The options are
OS Controls EPB
and BIOS
Controls EPB.
*If the feature above is set to BIOS Controls EPB, the following features will be
available for configuration:
ENERGY_PERF_BIAS_CFG Mode
The Energy Perfomance BIAS (EPB) feature allows the user to configure CPU power
and perfomance settings. Select Maximum Performance to set the highest performance.
Select Performance to optimize performance over energy efficiency. Select Balanced
Perfomance to priortize performance optimization while conserving energy. Select Bal-
anced Power to prioritize energy conservation while maintaining good performance.
Select Power to optimize energy efficency over performance. The options are Maximum
Performance, Performance,
Balanced Performance,
Balanced Power, and Power.
CPU P State Control
This feature allows the user to configure the following CPU power settings:
SpeedStep (Pstates)
Intel SpeedStep Technology allows the system to automatically adjust processor volt-
age and core frequency to reduce power consumption and heat dissipation. The options
are Disable and
Enable
. If this feature is set to Disabled, the next two features are not
available for configuration.
EIST PSD Funtion
This feature allows the user to choose between Hardware and Software to control the
processor's frequency and performance (P-state). In HW_ALL mode, the processor hard-
ware is responsible for coordinating the P-state, and the OS is responsible for keeping the
P-state request up to date on all Logical Processors. In SW_ALL mode, the OS Power
Manager is responsible for coordinating the P-state, and must initiate the transition on
all Logical Processors. In SW_ANY mode, the OS Power Manager is responsible for
coordinating the P-state and may initiate the transition on any Logical Processors. The
options are
HW_ALL
, SW_ALL, and SW_ANY.
Turbo Mode
This feature will enable dynamic control of the processor, allowing it to run above stock
frequency. The options are Disable and
Enable
.
