Mobile Intel Pentium 4 Processor Supporting Hyper-Threading Technology on 90-nm Process Technology

Mobile Intel® Pentium® 4 Processor Supporting Hyper-Threading Technology on 90-nm Process Technology Datasheet 59
Thermal Specifications and Design Considerations
5 Thermal Specifications and
Design Considerations
5.1 Processor Thermal Specifications
The processor requires a thermal solution to maintain temperatures within operating limits as set
forth in Section 5.1.1. Any attempt to operate the processor outside these operating limits may
result in permanent damage to the processor and potentially other components within the system.
As processor technology changes, thermal management becomes increasingly crucial when
building computer systems. Maintaining the proper thermal environment is key to reliable, long-
term system operation.
A complete thermal solution includes both component and system level thermal management
features. Component level thermal solutions can include active or passive heatsinks attached to the
processor Integrated Heat Spreader (IHS). Typical system level thermal solutions may consist of
system fans combined with ducting and venting.
This section provides data necessary for developing a complete thermal solution. For more
information on designing a component level thermal solution, consult your Intel field sales
representative.
5.1.1 Thermal Specifications
To allow for the optimal operation and long-term reliability of Intel processor-based systems, the
system/processor thermal solution should be designed such that the processor remains within the
minimum and maximum case temperature (T
C
) specifications at the corresponding Thermal
Design Power (TDP) value listed per frequency in Table 5-1. Thermal solutions not designed to
provide this level of thermal capability may affect the long-term reliability of the processor and
system. For more details on thermal solution design, please refer to the appropriate processor
thermal design guidelines.
The processor introduces a new methodology for managing processor temperatures through fan
speed control. Selection of the appropriate fan speed will be based on the temperature reported by
the processor’s Thermal Diode. The fan must be turned on to full speed when Tdiode is at or above
Tcontrol and T
C
must be maintained at or below T
C
(max) as defined by the processor thermal
specifications in Table 5-1. The fan speed may be lowered when the processor temperature can be
maintained below Tcontrol as measured by the thermal diode. Systems implementing fan speed
control must be designed to read temperature values from the diode and Tcontrol register and take
appropriate action. Systems that do not alter the fan speed (always at full speed) only need to
guarantee the case temperature meets specifications in Table 5-1.
The case temperature is defined at the geometric top center of the processor IHS. Analysis
indicates that real applications are unlikely to cause the processor to consume maximum power
dissipation for sustained time periods. Intel recommends that complete thermal solution designs
target the TDP indicated in Table 5-1 instead of the maximum processor power consumption. The
Intel
®
Thermal Monitor feature is intended to help protect the processor in the unlikely event that
an application exceeds the TDP recommendation for a sustained period of time. For more details
on the usage of this feature, refer to Section 5.2. To ensure maximum flexibility for future