Thermal Solution Design Process. Intel Xeon 3500 Series

Figure 5-3. Thermal solution Performance

Sensor Based Thermal Specification Design Guidance

5.3

5.3.1

Thermal Solution Design Process

Thermal solution design guidance for this specification is the same as with previous products. The initial design must take into account the target market and overall product requirements for the system. This can be broken down into several steps:

• Boundary condition definition

• Thermal design / modelling

• Thermal testing

Boundary Condition Definition

Using the knowledge of the system boundary conditions (e.g., inlet air temperature, acoustic requirements, cost, design for manufacturing, package and socket mechanical specifications and chassis environmental test limits) the designer can make informed thermal solution design decisions.

The thermal boundary conditions for an ATX tower system are as follows:

• T

EXTERNAL

= 35 °C. This is typical of a maximum system operating environment

• T

RISE

= 4 °C. This is typical of a chassis compliant to CAG 1.1

• T

AMBIENT

= 39 °C (T

AMBIENT

= T

EXTERNAL

+ T

RISE

)

Based on the system boundary conditions, the designer can select a T to use in thermal modelling. The assumption of a T

AMBIENT

AMBIENT

and Ψ

CA

has a significant impact on the required Ψ assumed T

CA

needed to meet TTV T

CASEMAX at TDP. A system that can deliver lower

AMBIENT

can utilize a design with a higher Ψ

CA

, which can have a lower cost.

Figure 5-4 shows a number of satisfactory solutions for the processor.

30 Thermal/Mechanical Design Guide