Intel 2 Duo T7400 LE80537GF0484M Manual Do Utilizador
Códigos do produto
LE80537GF0484M
Thermal Specifications and Design Considerations
88
Datasheet
designed thermal solution that is not able to prevent excessive activation of the TCC in
the anticipated ambient environment may cause a noticeable performance loss and
may affect the long-term reliability of the processor. In addition, a thermal solution that
is significantly under designed may not be capable of cooling the processor even when
the TCC is active continuously.
The Intel Thermal Monitor controls the processor temperature by modulating (starting
and stopping) the processor core clocks or by initiating an Enhanced Intel SpeedStep
Technology transition when the processor silicon reaches its maximum operating
temperature. The Intel Thermal Monitor uses two modes to activate the TCC:
Automatic mode and on-demand mode. If both modes are activated, automatic mode
takes precedence.
Note:
The Intel Thermal Monitor automatic mode must be enabled through BIOS for the
processor to be operating within specifications.
There are two automatic modes called Intel Thermal Monitor 1 and Intel Thermal
Monitor 2. These modes are selected by writing values to the MSRs of the processor.
After automatic mode is enabled, the TCC will activate only when the internal die
temperature reaches the maximum allowed value for operation.
Likewise, when Intel Thermal Monitor 2 is enabled and a high temperature situation
exists, the processor will perform an Enhanced Intel SpeedStep Technology transition
to a lower operating point. When the processor temperature drops below the critical
level, the processor will make an Enhanced Intel SpeedStep Technology transition to
the last requested operating point.
Intel Thermal Monitor 1 and Intel Thermal Monitor 2 can co-exist within the processor.
If both Intel Thermal Monitor 1 and Intel Thermal Monitor 2 bits are enabled in the
auto-throttle MSR, Intel Thermal Monitor 2 will take precedence over Intel Thermal
Monitor 1. However, if Intel Thermal Monitor 2 is not sufficient to cool the processor
below the maximum operating temperature then Intel Thermal Monitor 1 will also
activate to help cool down the processor. Intel recommends Intel Thermal Monitor 1
and Intel Thermal Monitor 2 be enabled on the processors.
If a processor load based Enhanced Intel SpeedStep Technology transition (through
MSR write) is initiated when an Intel Thermal Monitor 2 period is active, there are two
possible results:
1. If the processor load based Enhanced Intel SpeedStep Technology transition target
frequency is higher than the Intel Thermal Monitor 2 transition based target
frequency, the processor load-based transition will be deferred until the Intel
Thermal Monitor 2 event has been completed.
2. If the processor load-based Enhanced Intel SpeedStep Technology transition target
frequency is lower than the Intel Thermal Monitor 2 transition based target
frequency, the processor will transition to the processor load-based Enhanced Intel
SpeedStep Technology target frequency point.
When Intel Thermal Monitor 1 is enabled while a high temperature situation exists, the
clocks will be modulated by alternately turning the clocks off and on at a 50% duty
cycle. Cycle times are processor speed dependent and will decrease linearly as
processor core frequencies increase. Once the temperature has returned to a non-
critical level, modulation ceases and TCC goes inactive. A small amount of hysteresis
has been included to prevent rapid active/inactive transitions of the TCC when the
processor temperature is near the trip point. The duty cycle is factory configured and
cannot be modified. Also, automatic mode does not require any additional hardware,
software drivers, or interrupt handling routines. Processor performance will be
decreased by the same amount as the duty cycle when the TCC is active.