Intel E5-4600 Computer Hardware User Manual


 
42 Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
Datasheet Volume One
2.5.2.6.5 DIMM Ambient Temperature Write / Read
This feature allows the PECI host to provide an ambient temperature reference to be
used by the processor for activity-based DRAM temperature estimation. This write is
used only when no DIMM temperature information is available from on-board or on-die
DIMM thermal sensors. It is also possible for the PECI host controller to read back the
DIMM ambient reference temperature.
Since the ambient temperature may vary over time within a system, it is recommended
that systems monitoring and updating the ambient temperature at a fast rate use the
‘maximum’ temperature value while those updating the ambient temperature at a slow
rate use an ‘average’ value. The ambient temperature assumes a single value for all
memory channel/DIMM locations and does not account for possible temperature
variations based on DIMM location.
2.5.2.6.6 DRAM Channel Temperature Read
This feature enables a PECI host read of the maximum temperature of each channel.
This would include all the DIMMs within the channel and all the ranks within each of the
DIMMs. Channels that are not populated will return the ‘ambient temperature’ on
systems using activity-based temperature estimations or alternatively return a ‘zero’
for systems using sensor-based temperatures.
Figure 2-14. The Processor DIMM Temperature Read / Write
15 7 0
DIMM Temperature Data
Reserved
DIMM# 2
Absolute Temp
(in Degrees C)
DIMM# 1
Absolute Temp
(in Degrees C)
DIMM# 0
Absolute Temp
(in Degrees C)
816232431
15
2
Parameter format
Reserved Channel Index
3 0
Figure 2-15. Ambient Temperature Reference Data
7 0
Ambient Temperature Reference Data
Reserved
Ambient
Temperature
(in Degrees C)
831