Intel QX9775 EU80574XL088N 数据表
产品代码
EU80574XL088N
Datasheet
89
Features
6.3
Enhanced Intel SpeedStep
®
Technology
The processor supports Enhanced Intel SpeedStep
®
Technology. This technology
enables the processor to switch between multiple frequency and voltage points, which
results in platform power savings. Enhanced Intel SpeedStep
Technology requires
support for dynamic VID transitions in the platform. Switching between voltage/
frequency states is software controlled. For more configuration details also refer to the
Intel
®
64 and IA-32 Architectures Software Developer’s Manual.
Enhanced Intel SpeedStep Technology creates processor performance states (P-states)
or voltage/frequency operating points which are lower power capability states within
for the Stop Clock State Machine for supported P-
states). Enhanced Intel SpeedStep Technology enables real-time dynamic switching
between frequency and voltage points. It alters the performance of the processor by
changing the bus to core frequency ratio and voltage. This allows the processor to run
at different core frequencies and voltages to best serve the performance and power
requirements of the processor and system. The processor has hardware logic that
coordinates the requested voltage (VID) between the processor cores. The highest
voltage that is requested for either of the processor cores is selected for that processor
package. Note that the front side bus is not altered; only the internal core frequency is
changed. In order to run at reduced power consumption, the voltage is altered in step
with the bus ratio.
The following are key features of Enhanced Intel SpeedStep Technology:
• Multiple voltage/frequency operating points provide optimal performance at
reduced power consumption.
• Voltage/frequency selection is software controlled by writing to the processor MSR’s
(Model Specific Registers); thus, eliminating chipset dependency.
— If the target frequency is higher than the current frequency, V
CC
is incremented
in steps (+12.5 mV) by placing a new value on the VID signals and the
processor shifts to the new frequency. Note that the top frequency for the
processor can not be exceeded.
— If the target frequency is lower than the current frequency, the processor shifts
to the new frequency and V
CC
is then decremented in steps (-12.5 mV) by
changing the target VID through the VID signals.
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