Intel BX80635E51660V2 Computer Hardware User Manual


 
Interfaces
42 Intel® Xeon® Processor E5-1600 v2/E5-2600 v2 Product Families
Datasheet Volume One of Two
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.
2.5.2.6.7 Accumulated DRAM Energy Read
This feature allows the PECI host to read the DRAM energy consumed by all the DIMMs
within all the channels or all the DIMMs within just a specified channel. The parameter
field is used to specify the channel index. Units used are defined as per the Package
Power SKU Unit read described in Section 2.5.2.6.11. This information is tracked by a
32-bit counter that wraps around. The channel index in Figure 2-17 is specified as per
the index encoding described in Table 2-7. A channel index of 0x00FF is used to specify
the “all channels” case. While Intel requires reading the accumulated energy data at
least once every 16 seconds to ensure functional correctness, a more realistic polling
rate recommendation is once every 100 mS for better accuracy. This feature assumes a
200W memory capacity. In general, as the power capability decreases, so will the
minimum polling rate requirement.
When determining energy changes by subtracting energy values between successive
reads, Intel advocates using the 2’s complement method to account for counter
wraparounds. Alternatively, adding all ‘F’s (‘0xFFFFFFFF’) to a negative result from the
subtraction will accomplish the same goal.
Figure 2-15. Ambient Temperature Reference Data
7 0
Ambient Temperature Reference Data
Reserved
Ambient
Temperature
(in Degrees C)
831
Figure 2-16. Processor DRAM Channel Temperature
15 7 0
Channel Temperature Data
Channel 3
Maximum
Temperature
(in Degrees C)
Channel 2
Maximum
Temperature
(in Degrees C)
Channel 1
Maximum
Temperature
(in Degrees C)
Channel 0
Maximum
Temperature
(in Degrees C)
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