Datasheet

Pentium

III Xeon™ Processor at 500 and 550 MHz

Datasheet

5.1 Thermal Specifications

This section provides power dissipation specifications for each variation of the Pentium

III

Xeon

processor. The thermal plate flatness is also specified for the S.E.C. cartridge.

5.1.1 Power Dissipation

Table 38 provides the thermal design power dissipation for Pentium

III

Xeon processors. While the

processor core dissipates the majority of the thermal power, the system designer should also be

aware of the thermal power dissipated by the second level cache. Systems should design for the

highest possible thermal power, even if a processor with lower frequency or smaller second level

cache is planned. The thermal plate is the attach location for all thermal solutions. The maximum

temperature for the entire thermal plate surface is shown in Table 38.

The processor power is dissipated through the thermal plate and other paths. The power dissipation

is a combination of power from the processor core, the second level cache and the AGTL+ bus

termination resistors. The overall system thermal design must comprehend the total processor

power. The combined power from the processor core and the second level cache that dissipates

through the thermal plate is the thermal plate power. The heatsink should be designed to dissipate

the thermal plate power.

The thermal sensor feature of the processor cannot be used to measure T

PLATE

. The T

PLATE

specification must be met regardless of the reading of the processor's thermal sensor in order to

ensure adequate cooling for the entire Pentium

III

Xeon processor.

Figure 18. Thermal Plate View