Intel i5-2540M FF8062700839209 Manuale Utente

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Datasheet

However, an under-designed thermal solution that is not able to prevent excessive 

assertion of PROCHOT# in the anticipated ambient environment may:

• Cause a noticeable performance loss.
• Result in prolonged operation at or above the specified maximum junction 

temperature and affect the long-term reliability of the processor.

• May be incapable of cooling the processor even when the TCC is active continuously 

(in extreme situations).

If the processor enters a low-power package idle state such as C3 or C6 with 

PROCHOT# asserted, PROCHOT# will remain asserted until:

• The processor exits the low-power state
• The processor junction temperature drops below the thermal trip point.

Note that the PECI interface is fully operational during all C-states and it is expected 

that the platform continues to manage processor core thermals even during idle states 

by regularly polling for thermal data over PECI.

The processor provides an auxiliary mechanism that allows system software to force 

the processor to reduce its power consumption via clock modulation. This mechanism is 

referred to as “On-Demand” mode and is distinct from Adaptive Thermal Monitor and 

bi-directional PROCHOT#. Intel Core i7-600, i5-500, i5-400 and i3-300 Mobile 

Processor Series platforms must not rely on software usage of this mechanism to limit 

the processor temperature. On-Demand Mode can be done via processor MSR or 

chipset I/O emulation.

On-Demand Mode may be used in conjunction with the Adaptive Thermal Monitor. 

However, if the system software tries to enable On-Demand mode at the same time the 

TCC is engaged, the factory configured duty cycle of the TCC will override the duty 

cycle selected by the On-Demand mode. If the I/O based and MSR-based On-Demand 

modes are in conflict, the duty cycle selected by the I/O emulation-based On-Demand 

mode will take precedence over the MSR-based On-Demand Mode. 

If Bit 4 of the IA32_CLOCK_MODULATION MSR is set to a 1, the processor will 

immediately reduce its power consumption via modulation of the internal core clock, 

independent of the processor temperature. The duty cycle of the clock modulation is 

programmable via Bits 3:1 of the same IA32_CLOCK_MODULATION MSR. In this mode, 

the duty cycle can be programmed from 12.5% on/87.5% off to 87.5% on/12.5% off in 

12.5% increments. Thermal throttling using this method will modulate each processor 

core’s clock independently.

I/O emulation-based clock modulation provides legacy support for operating system 

software that initiates clock modulation through I/O writes to ACPI defined processor 

clock control registers on the chipset (PROC_CNT). Thermal throttling using this 

method will modulate all processor cores simultaneously.