Nettop Platform for 2008 System Design White Paper

Improving System Thermal Performance
24 White Paper
5 Improving System Thermal
Performance
The heat generated by components within the chassis must be removed to provide an
adequate operating environment for the processor and all other components in the
system. Moving airflow through the chassis brings in fresh cool air from the external
ambient environment and transports the heat generated by the processor and other
system components out of the system. Therefore, the number, size and relative
position of fans and vents determine the chassis thermal performance, and the
resulting ambient temperature around the processor.
To look at thermal design consideration from point of system configuration, it’s
important to point out that system boundary condition is the most critical and
underlining parameters of all. System boundary condition, which is airflow and the
ambient condition of the system, is related to heatsink design and component
characteristic. It is particularly important to choose a thermally advantaged chassis
for the reference thermal solution for Intel
®
Atom™ processor 200 series on Intel
®
Desktop Board D945GCLF, for building a nettop system.
5.1 Typical Thermal Solutions
The typical thermal solutions include active, passive and fanless type of solution.
An active thermal solution has a fan (either axial or blower type fan) directly mounted
on heatsink as an unified heat removal device. System acoustic (from heatsink fan)
and cost are the common trade-offs for an active heatsink.
Passive thermal solution is a thermal solution without fan, which relies on system fan
to provide airflow for cooling. System acoustic concern shifts to system fan in this
case. The cost is obviously reduced.
Fanless thermal solution is capable of cooling inside a system that does not have any
fan, and no moving parts or what so ever. Natural convection is the primary heat
transfer mechanism, therefore system ventilation is key factors for good thermal
performance of fanless thermal solution.
It is obvious that the thermal performance of a passive or fanless thermal solution is
highly dependent on system configuration.