Michael A. Tharp PE

Project 2u - Thermal Modeling Summary

Modeling Assumptions

· Conditions of 35 Deg C Ambient Air at Sea Level

• Maximum Mother Board Power Dissipation Total of 443 Watts

• Power Supply and Device Bay Component Power Not Included in First Model

• EMI grills in front and back with 51 % free area ratio

• Front-to-Back Air Flow

• Three 80 mm Fans in Front of Unit , Provide 80 CFM each at Free Delivery

• Two 60 mm Processor Fans on two Xeon Heat Sinks , Provide 24.4 CFM at Free Delivery, Fan heat loads are small and are currently not included in the model.

• Run initial baseline scenario

• Processor Heat Sinks are Aluminum, and Do Not include a fan shroud in this model.

• Baseline Case 1. Three 80mm fans front-to-back air flow, 2 Processor Fans

Updated Model Results- Second Pass

For the baseline configuration thermal model the predicted XEON component case temperatures are under the Intel 72 C case temperature maximum design limit. Predicted maximum temperatures for two processors after model mesh refinements have been

reduced from the first pass estimate of 71 C to 65 C for a 35 C ambient inlet air temperature.

The 60 mm processor fan operating point is 14.9 CFM (no heat sink shroud)

The three 80 mm fans operating points are now at approximately 32 CFM each.

Flow rate through the entire system inlet and exit grills is 95 CFM at a system pressure drop of 0.458 inches of water.

Conclusion

The number of fans, system air flow, and heat sinks provide adequate cooling for the design conditions modeled. There are no major thermal management issues revealed in the first pass system thermal model for the proposed mother board design layout.

Figure 1. Cad and Model Component Layout

Figure 2. ICEPAK THERMAL MODEL

Table 1. Maximum Predicted Temperatures for Components

Xeon 3.6 GHZ 64.94 C

Xeon 3.6 GHZ.1 65.15 C

Anvik 111 C

Anvik.1 114.1 C

Anvik.2 113.4 C

Anvik.3 110.4 C

Anvik.4 106.1 C

BCM5823 87.93 C

BCM5823.1 77.7 C

MCH 68.71 C

PXH.1 81.12 C

PXH.1.1 67.96 C

PXH 64.06 C

DDR_CCA 85.08 C

DDR 77.01 C

DDR.1 79.26 C

DDR.2 81.1 C

DDR.3 82.65 C

DDR.4 83.89 C

DDR.5 84.75 C

DDR.6 85.1 C

DDR.7 85.02 C

DDR.8 84.11 C

DDRs 77.13 C

DDRs.1 79.35 C

DDRs.2 81.19 C

DDRs.3 82.73 C

DDRs.4 83.92 C

DDRs.5 84.65 C

DDRs.6 85.04 C

DDRs.7 84.89 C

DDRs.8 83.9 C

DDR_CCA.1 88.04 C

DDR.1.1 80.3 C

DDR.2.1 82.22 C

DDR.3.1 83.96 C

DDR.4.1 85.51 C

DDR.5.1 86.75 C

DDR.6.1 87.68 C

DDR.7.1 88.06 C

DDR.8.1 87.58 C

DDR.9 78.11 C

DDRs.1.1 80.23 C

DDRs.2.1 82.15 C

DDRs.3.1 83.89 C

DDRs.4.1 85.43 C

DDRs.5.1 86.67 C

DDRs.6.1 87.62 C

DDRs.7.1 88 C

DDRs.8.1 87.52 C

DDRs.9 78.05 C

DDR_CCA.2 88.21 C

DDR.1.2 80.43 C

DDR.2.2 82.37 C

DDR.3.2 84.11 C

DDR.4.2 85.62 C

DDR.5.2 86.83 C

DDR.6.2 87.79 C

DDR.7.2 88.21 C

Table 1. Predicted Temperatures for Components( Continued.)

DDR.8.2 87.77 C

DDR.10 78.21 C

DDRs.1.2 80.44 C

DDRs.2.2 82.39 C

DDRs.3.2 84.13 C

DDRs.4.2 85.65 C

DDRs.5.2 86.87 C

DDRs.6.2 87.82 C

DDRs.7.2 88.23 C

DDRs.8.2 87.79 C

DDRs.10 78.21 C

DDR_CCA.3 86.36 C

DDR.1.3 79.45 C

DDR.2.3 81.2 C

DDR.3.3 82.71 C

DDR.4.3 83.97 C

DDR.5.3 84.92 C

DDR.6.3 85.45 C

DDR.7.3 85.49 C

DDR.8.3 84.67 C

DDR.11 77.37 C

DDRs.1.3 79.34 C

DDRs.2.3 81.11 C

DDRs.3.3 82.66 C

DDRs.4.3 83.95 C

DDRs.5.3 84.89 C

DDRs.6.3 85.54 C

DDRs.7.3 85.63 C

DDRs.8.3 84.88 C

DDRs.11 77.22 C

Table 2. Fan Operating Points

Fan Operating Points:

80mmfan.1 Volume flow = 1.492e-002 m3/s, pressure rise = 114.06250970495 N/m2

80mmfan.2.1 Volume flow = 1.506e-002 m3/s, pressure rise = 113.15651932065 N/m2

80mmfan.2 Volume flow = 1.498e-002 m3/s, pressure rise = 113.7114823827 N/m2

60mmfan Volume flow = 7.059e-003 m3/s, pressure rise = 17.344809186702 N/m2

60mmfan.1 Volume flow = 7.447e-003 m3/s, pressure rise = 15.835070226611 N/m2

Table 3. Model Heat Load Input for Objects with Power Specified:

Object Specified Calculated

Anvik 2.61 W 2.61 W

Anvik.1 2.61 W 2.61 W

Anvik.2 2.61 W 2.61 W

Anvik.3 2.61 W 2.61 W

Anvik.4 2.61 W 2.61 W

BCM5823 0.9 W 0.9003 W

BCM5823.1 0.9 W 0.9002 W

DDR 0.5093 W 0.5093 W

DDR.1 0.5093 W 0.5094 W

DDR.2 0.5093 W 0.5094 W

DDR.3 0.5093 W 0.5093 W

DDR.4 0.5093 W 0.5095 W

DDR.5 0.5093 W 0.5094 W

DDR.6 0.5093 W 0.5094 W

DDR.7 0.5093 W 0.5094 W

DDR.8 0.5093 W 0.5094 W

DDRs 0.5093 W 0.5092 W

DDRs.1 0.5093 W 0.5092 W

DDRs.2 0.5093 W 0.5093 W

DDRs.3 0.5093 W 0.5094 W

DDRs.4 0.5093 W 0.5093 W

DDRs.5 0.5093 W 0.5094 W

DDRs.6 0.5093 W 0.5093 W

DDRs.7 0.5093 W 0.5093 W

DDRs.8 0.5093 W 0.5093 W

DDR.1.1 0.5093 W 0.5093 W

DDR.2.1 0.5093 W 0.5093 W

DDR.3.1 0.5093 W 0.5092 W

DDR.4.1 0.5093 W 0.5092 W

DDR.5.1 0.5093 W 0.5093 W

DDR.6.1 0.5093 W 0.5092 W

DDR.7.1 0.5093 W 0.5092 W

DDR.8.1 0.5093 W 0.5093 W

DDR.9 0.5093 W 0.5092 W

DDRs.1.1 0.5093 W 0.5093 W

DDRs.2.1 0.5093 W 0.5093 W

DDRs.3.1 0.5093 W 0.5093 W

DDRs.4.1 0.5093 W 0.5094 W

DDRs.5.1 0.5093 W 0.5093 W

DDRs.6.1 0.5093 W 0.5093 W

DDRs.7.1 0.5093 W 0.5093 W

DDRs.8.1 0.5093 W 0.5093 W

DDRs.9 0.5093 W 0.5093 W

DDR.1.2 0.5093 W 0.5093 W

DDR.2.2 0.5093 W 0.5094 W

DDR.3.2 0.5093 W 0.5093 W

DDR.4.2 0.5093 W 0.5093 W

DDR.5.2 0.5093 W 0.5094 W

DDR.6.2 0.5093 W 0.5093 W

DDR.7.2 0.5093 W 0.5094 W

DDR.8.2 0.5093 W 0.5094 W

DDR.10 0.5093 W 0.5093 W

DDRs.1.2 0.5093 W 0.5093 W

DDRs.2.2 0.5093 W 0.5094 W

DDRs.3.2 0.5093 W 0.5093 W

DDRs.4.2 0.5093 W 0.5093 W

DDRs.5.2 0.5093 W 0.5093 W

Table 3. Model Heat Load Input ( Continued)

DDRs.6.2 0.5093 W 0.5093 W

DDRs.7.2 0.5093 W 0.5092 W

DDRs.8.2 0.5093 W 0.5093 W

DDRs.10 0.5093 W 0.5093 W

DDR.1.3 0.5093 W 0.5092 W

DDR.2.3 0.5093 W 0.5093 W

DDR.3.3 0.5093 W 0.5093 W

DDR.4.3 0.5093 W 0.5093 W

DDR.5.3 0.5093 W 0.5093 W

DDR.6.3 0.5093 W 0.5092 W

DDR.7.3 0.5093 W 0.5092 W

DDR.8.3 0.5093 W 0.5092 W

DDR.11 0.5093 W 0.5092 W

DDRs.1.3 0.5093 W 0.5093 W

DDRs.2.3 0.5093 W 0.5094 W

DDRs.3.3 0.5093 W 0.5093 W

DDRs.4.3 0.5093 W 0.5093 W

DDRs.5.3 0.5093 W 0.5093 W

DDRs.6.3 0.5093 W 0.5094 W

DDRs.7.3 0.5093 W 0.5093 W

DDRs.8.3 0.5093 W 0.5094 W

DDRs.11 0.5093 W 0.5093 W

MCH 9.7 W 9.7 W

PXH.1 8.1 W 8.1 W

PXH.1.1 8.1 W 8.1 W

PXH 8.1 W 8.1 W

Unformly Spread on Mother_Board 123.5 W 123.5 W

PCI_FULL_CCA2 14 W 14 W

PCI_Full_CCA 14 W 14 W

Xeon 3.6 GHZ 103.0 103 W

Xeon 3.6 GHZ.1 103.0 103 W

Overall Totals:

Total power = 443 W

Figure 3. Air Velocity Across Motherboard

Figure4. Air Temperature Rise Across Motherboard

Figure 3. Motherboard Device Temperatures