Embedded Thermal Solutions
92
Thermal/Mechanical Design Guide
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
Section 5.1
for standard 1U solutions that do not need to meet NEBS.
Detailed drawings for the ATCA reference heatsink can be found in
Section E.3
.
Table E-1
and
Table E-2
above specify
CA
targets.
Figure E-1
below shows
CA
and
pressure drop for the ATCA heatsink versus the airflow provided. Best-fit equations are
provided to prevent errors associated with reading the graph.
Other LGA1366 compatible thermal solutions may work with the same retention.
E.2
Thermal Design Guidelines
E.2.1
NEBS Thermal Profile
Processors that offer a NEBS compliant thermal profile are specified in the appropriate
Datasheet.
NEBS thermal profiles help relieve thermal constraints for Short-Term NEBS conditions.
To help reliability, processors must meet the nominal thermal profile under standard
operating conditions and can only rise up to the Short-Term spec for NEBS excursions
(see
Figure E-2
). The definition of Short-Term time is clearly defined for NEBS Level 3
conditions but the key is that it cannot be longer than 360 hours per year.
Figure E-1. ATCA Heatsink Performance Curves
0
0.4
0.8
1.2
1.6
2
0
0.5
1
1.5
2
2.5
0
5
10
15
20
25
30
35
CFM Through Fins
P = 1.3e-1.1e-02CFM
Mean
ca
= 0.337 + 1.625 CFM
-0.939
Summary of Contents for X5550 - Quad Core Xeon
Page 8: ...8 Thermal Mechanical Design Guide ...
Page 12: ...Introduction 12 Thermal Mechanical Design Guide ...
Page 24: ...Independent Loading Mechanism ILM 24 Thermal Mechanical Design Guide Figure 3 3 ILM Assembly ...
Page 26: ...Independent Loading Mechanism ILM 26 Thermal Mechanical Design Guide ...
Page 48: ...Component Suppliers 48 Thermal Mechanical Design Guide ...
Page 82: ...Mechanical Drawings 82 Thermal Mechanical Design Guide ...
Page 88: ...Socket Mechanical Drawings 88 Thermal Mechanical Design Guide ...
