Intel 945GZ ユーザーズマニュアル

20  

 

Thermal and Mechanical Design Guidelines 

Proc_HS_Orient_ATX

Omi Directional Flow

Processor Heatsink

(Fan Not Shown)

 

Other methods exist for providing airflow to the (G)MCH heatsink, including the use of 

system fans and/or ducting, or the use of an attached fan (active heatsink). 

The operating environment for the (G)MCH in typical BTX systems has not been 

profiled. This section provides operating environment conditions based on what has 

been exhibited on the Intel micro-BTX reference design. On a BTX platform, the 

(G)MCH obtains in-line airflow directly from the processor thermal module. Since the 

processor thermal module provides lower inlet temperature airflow to the processor, 

reduced inlet ambient temperatures are also often seen at the (G)MCH as compared to 

ATX. An example of how airflow is delivered to the (G)MCH on a BTX platform is 

shown in Figure 6. 

The local ambient air temperature, T

A

, at the (G)MCH heatsink in the Intel micro-BTX 

reference design is predicted to be ~45 °C. The thermal designer must carefully select 

the location to measure airflow to get a representative sampling. These environmental 

assumptions are based on a 35 °C system external temperature measured at sea 

level. 

Note:  The local ambient air temperature is a projection based on anticipated power 

increases on a 2005 platform and may be subject to change in future revisions of this 
document.