Thermal/Mechanical Specifications and Design Guidelines
69
Sensor Based Thermal Specification Design Guidance
Note:
When selecting a thermal solution from a thermal vendor, the characterization data
should be requested directly from them as a part of their thermal solution collateral.
Note:
This data is taken from the preliminary evaluation of the validation of the RCBF7-1156
(DHA-A) reference processor thermal solution. The
CA
versus RPM data is available in
at the end of this chapter.
8.4
Fan Speed Control (FSC) Design Process
The next step is to incorporate the thermal solution characterization data into the
algorithms for the device controlling the fans.
As a reminder the requirements are:
• When the DTS value is at or below T
CONTROL
, the fans can be slowed down - just as
with prior processors.
• When DTS is above T
CONTROL
, FSC algorithms will use knowledge of T
AMBIENT
and
CA
versus RPM to achieve the necessary level of cooling.
DTS 1.1 provides another option to do fan speed control without the Tambient data.
Please refer to
for more details.This chapter will discuss two
implementations. The first is a FSC system that is not provided the T
AMBIENT
information and a FSC system that is provided data on the current T
AMBIENT
. Either
method will result in a thermally compliant solution and some acoustic benefit by
operating the processor closer to the thermal profile. But only the T
AMBIENT
aware FSC
system can fully utilize the specification for optimized acoustic performance.
In the development of the FSC algorithm it should be noted that the T
AMBIENT
is
expected to change at a significantly slower rate than the DTS value. The DTS value will
be driven by the workload on the processor and the thermal solution will be required to
respond to this much more rapidly than the changes in T
AMBIENT
.
Figure 8-5. Thermal Solution Performance versus Fan Speed
RPM vs. Measured Thermal Performance
0.300
0.350
0.400
0.450
15
00
20
00
25
00
30
00
35
00
RPM
P
si
-ca (
°C
/W
)
Summary of Contents for 2ND GENERATION CORE PROCESSOR FAMILY DESKTOP - THERMAL MECHANICAL S AND DESIGN GUIDELINES 01-2011
Page 12: ...Introduction 12 Thermal Mechanical Specifications and Design Guidelines...
Page 36: ...Independent Loading Mechanism ILM 36 Thermal Mechanical Specifications and Design Guidelines...
Page 62: ...PECI Interface 62 Thermal Mechanical Specifications and Design Guidelines...
Page 88: ...ATX Reference Thermal Solution 88 Thermal Mechanical Specifications and Design Guidelines...
Page 102: ...Boxed Processor Specifications 102 Thermal Mechanical Specifications and Design Guidelines...
Page 120: ...Mechanical Drawings 120 Thermal Mechanical Specifications and Design Guidelines...
Page 126: ...Socket Mechanical Drawings 126 Thermal Mechanical Specifications and Design Guidelines...
Page 130: ...Package Mechanical Drawings 130 Thermal Mechanical Specifications and Design Guidelines...
