Intel Core 2 Duo E7300 BX80570E7300 User Manual

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Thermal and Mechanical Design Guidelines  

To optimize acoustic emission by the fan heatsink assembly, the Type II reference 

design implements a variable speed fan. A variable speed fan allows higher thermal 

performance at higher fan inlet temperatures (T

A

) and the appropriate thermal 

performance with improved acoustics at lower fan inlet temperatures. Using the 
example in Table 

5–2 for the Intel Core™2 Duo processor with 4 MB cache at Tc-max 

of 60.1° C the required fan speed necessary to meet thermal specifications can be 

controlled by the fan inlet temperature and should comply with requirements in the 

following table.  

 

Requirements, ca 

~ 5300 

High 
T

A

 ≥ 35° C 

 6.4 BA 

0.38 C/W  
 
 

Case 1: 
Thermal Design Power 
Maximum fan speed  
100% PWM duty cycle 

~ 2500 

Low 
T

A

 = 23° C 

No Target 
Defined 

0.56 C/W  
 
 

Case 2 
Thermal Design Power 
System (PSU, HDD, TMA) 
Fan speed limited by the fan 
hub thermistor  

~ 1400 

Low 
T

A

 = 23° C 

3.4 BA 

~0.87 C/W 

Case 3 
50% Thermal Design Power 
TMA Only 

~ 1400 

Low 
T

A

 = 23° C 

4.0 BA 

~0.87 C/W  
 
 

Case 3 
50% Thermal Design Power 
System (PSU, HDD, TMA) 

NOTES:  

1. 

Acoustic performance is defined in terms of measured sound power (LwA) as defined in 

ISO 9296 standard, and measured according to ISO 7779.  

2. 

Acoustic testing will be for the TMA only when installed in a BTX S2 chassis for Case 1 

and 3 

3. 

Acoustics testing for Case 2 will be system level in the same a BTX S2 reference chassis 

and commercially available power supply. Acoustic data for Case 2 will be provided in 

the validation report but this condition is not a target for the design. The acoustic model 

is predicting that the power supply fan will be the acoustic limiter.  

4. 

The fan speeds (RPM) are estimates for one of the two reference fans and will be 

adjusted to meet thermal performance targets then acoustic target during validation. 

The designer should identify the fan speed required to meet the effective fan curve 
shown in Section 

While the fan hub thermistor helps optimize acoustics at high processor workloads by 

adapting the maximum fan speed to support the processor thermal profile, additional 

acoustic improvements can be achieved at lower processor workload by using the 
T

CONTROL

 specifications described in Section 

2.2.4. Intel’s recommendation is to use the 

fan with 4 Wire PWM Controlled to implement fan speed control capability based the 
digital thermal sensor. Refer to Chapter 

7 for further details.  

Appendix F gives detailed fan performance for the Intel reference thermal solutions 
with 4 Wire PWM Controlled fan.