Intel Core 2 Duo E7300 BX80570E7300 User Manual

56  

 

Thermal and Mechanical Design Guidelines  

To optimize acoustic emission by the fan heatsink assembly, the reference design 

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

performance at higher fan inlet temperatures (T

A

) and lower thermal performance with 

improved acoustics at lower fan inlet temperatures. The required fan speed necessary 

to meet thermal specifications can be controlled by the fan inlet temperature and 
should comply with requirements in Table 

6–2.  

 

ca Notes 

3900 

High 
T

A

 = 40° C 

5.0 BA 

  0.50 C/W (Core™2 Duo processor E8000 series 6 

MB)  

  0.52 C/W (Core™2 Duo processor E7000 series 3 

MB, Pentium dual-core processor E6000, E5000 

series 2 MB, and Intel

®

 Celeron

®

  processor E3x00 

series with 1 MB) 

 

2000 

Low 
T

A

 = 30° C  

3.5 BA 

  0.65 C/W (Core™2 Duo processor E8000 series 

with 6 MB) 

  0.68 C/W (Core™2 Duo processor E7000 series 3 

MB, Pentium dual-core processor E6000, E5000 

series 2 MB, and Intel

®

 Celeron

®

   processor 

E3x00 series with 1 MB)  

Thermal Design 
Power, Fan 
speed limited 
by the fan hub 
thermistor 

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.  

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 recommendation is to use the 

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

Many companies design products that must function reliably at high altitude, typically 

1,500 m [5,000 ft] or more. Air-cooled temperature calculations and measurements at 

the test site elevation must be adjusted to take into account altitude effects like 

variation in air density and overall heat capacity. This often leads to some degradation 

in thermal solution performance compared to what is obtained at sea level, with lower 

fan performance and higher surface temperatures. The system designer needs to 

account for altitude effects in the overall system thermal design to make sure that the 

T

C

 requirement for the processor is met at the targeted altitude.