Intel 2ND GENERATION CORE PROCESSOR FAMILY DESKTOP - THERMAL MECHANICAL S AND DESIGN GUIDELINES 01-2011, Specifications

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Thermal Specifications
58 Thermal/Mechanical Specifications and Design Guidelines
Enabling Intel ® Turbo Boost Technology will maximize the performance of the
processor core and the graphics render frequency within the specified package power
levels. Compared with previous generation products, Intel
® Turbo Boost Technology
will increase the ratio of application power to TDP. Thus, thermal solutions and platform
cooling that are designed to less than thermal design guidance might experience
thermal and performance issues since more applications will tend to run at the
maximum power limit for significant periods of time.
6.4 Thermal Considerations
Intel Turbo Boost Technology allows processor cores and Processor Graphics cores to
run faster than the baseline frequency. During a turbo event, the processor can exceed
its TDP power for brief periods. Turbo is invoked opportunistically and automatically as
long as the processor is conforming to its temperature, power delivery, and current
specification limits. Thus, thermal solutions and platform cooling that are designed to
be less than thermal design guidance may experience thermal and performance issues
since more applications will tend to run at or near the maximum power limit for
significant periods of time.
6.4.1 Intel ® Turbo Boost Technology Power Control and
Reporting
When operating in the turbo mode, the processor will monitor its own power and adjust
the turbo frequency to maintain the average power within limits over a thermally
significant time period. The package, processor core, and graphic core powers are
estimated using architectural counters and do not rely on any input from the platform.
The behavior of turbo is dictated by the following controls that are accessible using
MSR, MMIO, or PECI interfaces:
• POWER_LIMIT_1 : TURBO_POWER_LIMIT, MSR 610h, bits 14:0. This value sets
the exponentially weighted moving average power limit over a long time period.
This is normally aligned to the TDP of the part and steady-state cooling capability of
the thermal solution. This limit may be set lower than TDP, real-time, for specific
needs, such as responding to a thermal event. If set lower than TDP, the processor
may not be able to honor this limit for all workloads since this control only applies
in the turbo frequency range; a very high powered application may exceed
POWER_LIMIT_1, even at non-turbo frequencies. The default value is the TDP for
the SKU.
• POWER_LIMIT_1_TIME : TURBO _POWER_LIMIT, MSR 610h, bits 23:17. This
value is a time parameter that adjusts the algorithm behavior. The exponentially
weighted moving average turbo algorithm will use this parameter to maintain time
averaged power at or below POWER_LIMIT_1. The default and recommended is 1
second for desktop applications.
• POWER_LIMIT_2 : TURBO_POWER_LIMIT, MSR 610h, bits 46:32. This value
establishes the upper power limit of turbo operation above TDP, primarily for
platform power supply considerations. Power may exceed this limit for up to
10 mS. The default for this limit is 1.25 x TDP.