Platform Controller Hub (Pch) Cooling; Voltage Regulator Cooling; Figure 4-4. Air Temperature Increase Across Memory - Intel Thin Mini-ITX System Design Manual

Thermals & Acoustics
also meet board routing constraints. This introduces a cooling challenge that will
require careful consideration in how air is pulled through the system from the inlet
vents, through the air moving device and then out exit vents. Since multiple memory
chips are placed on each SO-DIMM the air temperature that a particular chip
experiences can be affected by the overall direction of the airflow over the SD-DIMM
module. Maximum (undesirable) chip temperatures occur when the predominant air
flow direction is along the long dimension of the SD-DIMM module. Cooling of the
DRAM chips improves with an increase in the local velocity. Therefore, any inlet vents
near the SO-DIMMs should be sized to produce maximum velocity without producing
too much pressure drop.

Figure 4-4. Air Temperature Increase Across Memory

4.3.2

Platform Controller Hub (PCH) Cooling

The location of the PCH may vary from board to board. Therefore, system airflow
should be designed to take that variability into account. But it is recommended that
motherboard designers follow the same core layout as the Intel reference design to
mitigate this effort.
See Intel's Thermal Mechanical Design Guide for the applicable Intel chipset to obtain
explicit thermal boundary condition requirements for the PCH.
4.3.3

Voltage Regulator Cooling

• Voltage regular designs can vary from board supplier to board supplier.
Therefore, a system designer must avoid having stagnant airflow in the region of the
voltage regulator components. The best solution is to provide a system fan directed
toward the voltage regulator region.
• A larger number of phases will produce lower component temperatures because
the power is divided out among more components. Hence a three phase VR is
thermally a much better choice over a two phase VR.
• Strategically placed chassis vents can help to ensure an airflow path goes through
the VR region.
Thin Mini-ITX Based PC System Design Guide
Air temperature increases
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