User's Manual

Product Specifications
14 Thermal and Mechanical Design Guidelines
2.4.1 Methodology
2.4.1.1 Pre-Silicon
To determine TDP for pre-silicon products in development, it is necessary to make
estimates based on analytical models. These models rely on extensive knowledge of
the past chipset power dissipation behavior along with knowledge of planned
architectural and process changes that may affect TDP. Knowledge of applications
available today and their ability to stress various components of the chipset is also
included in the model. Since the number of applications available today is beyond
what Intel can test, only real world high-power applications are tested to predict TDP.
The values determined are used to set specific data transfer rates. The projection for
TDP assumes (G)MCH operation at T
C-MAX
. The TDP estimate also includes a margin to
account for process variation.
2.4.1.2 Post-Silicon
Once the product silicon is available, post-silicon validation is performed to assess the
validity of pre-silicon projections. Testing is performed on both commercially available
and synthetic high power applications and power data is compared to pre-silicon
estimates. Post-silicon validation may result in a small adjustment to pre-silicon TDP
estimates.
2.4.2 Application Power
Designing to the TDP can ensure that a particular thermal solution meets the cooling
needs of future applications. Testing with currently available commercial applications
has shown that the components may dissipate power levels below the published TDP
specification in Section
2.4.3. Intel strongly recommends that thermal engineers
design to the published TDP specification to develop a robust thermal solution that will
meet the needs of current and future applications.
2.4.3 Specifications
The (G)MCH is estimated to dissipate the Thermal Design Power values provided in
Table 3 when using two DIMMs of 667 MHz (553 MHz for the 82945PL/82945GZ) dual
channel DDR2 with a 1066 MHz (800 MHz for the 82945PL/82945GZ/82945GC)
processor system bus speed. For the 82945G/82945GZ/82945GC GMCH, the graphics
core is assumed to run at 400 MHz. FC-BGA packages have limited heat transfer
capability into the board and have minimal thermal capability without thermal
solutions. Intel requires that system designers plan for an attached heatsink when
using the (G)MCH.
Table 3. (G)MCH Thermal Design Power Specifications
Component System Bus Speed Memory Frequency TDP Value
82945G GMCH
1066 MHz 667 MHz
22.2 W
82945GZ GMCH
800 MHz 533 MHz
22.2 W
82945GC GMCH
800 MHz 667 MHz
22.2 W
82945P MCH
1066 MHz 667 MHz
15.2 W
82945PL MCH
800 MHz 533 MHz
15.2 W
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