Lenovo Intel Xeon E5520 67Y0011 Manuale Utente

Thermal/Mechanical Design Guide

87

This section describes the LV processors and Embedded reference heatsinks for NEBS 
(Network Equipment Building Systems) compliant ATCA (Advanced Telecommunications 
Computing Architecture) systems. These LV processors are good for any form factor 
that needs to meet NEBS requirements. 

 provides boundary conditions and performance targets for 1U and ATCA 

heatsinks. These values are used to generate processor thermal specifications and to 
provide guidance for heatsink design.

1. Local ambient temperature of the air entering the heatsink.

2. Max target (mean + 3 sigma + offset) for thermal characterization parameter (

). 

3. Reference system configuration. In a single wide ATCA blade the 60 W processor should be used in single

socket only and the 38 W processor can be used in dual socket.

4. Local Ambient Temperature written 50/65

o

 C means 50

o 

C under Nominal conditions but 65

o 

C is allowed for

Short-Term NEBS excursions. 

5. Passive heatsinks with TIM. 

6. See 

 for standard 1U solutions that do not need to meet NEBS.

Altitude, system ambient temp 

Nominal/Short-term

Sea level, 40

o 

C/55C

Sea level, 40

o 

C/55C

TDP

60 W

38 W

T

LA

1,4

51.9/66.9

o 

C

50/65

o 

C

Ψ

CA

2

0.302

o 

C/W

0.532

o 

C/W

System height (form factor)

3

1U (EEB) or ATCA

ATCA

Heatsink volumetric

1U (90 x 90 x 27) or Custom ATCA 

(90 x 90 x 13mm + heat 

exchanger) 

ATCA (90 x 90 x 13 mm)

Heatsink technology

5

Cu base, Cu fins