Penguin Computing Relion 1900e, Technical Manual

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Relion 1900e/2900e Manual
have valid temp sensors and some do not) is not supported. The BMC fan speed control functionality is
related to the memory throttling mechanism used.
The following terminology is used for the various memory throttling options:
• Static Closed Loop Thermal Throttling (Static-CLTT): CLTT control registers are configured by
BIOS MRC during POST. The memory throttling is run as a closed-loop system with the DIMM
temperature sensors as the control input. Otherwise, the system does not change any of the
throttling control registers in the embedded memory controller during runtime.
•
Dynamic Closed Loop Thermal Throttling (Dynamic-CLTT): CLTT control registers are
configured by BIOS MRC during POST. The memory throttling is run as a closed-loop system with
the DIMM temperature sensors as the control input. Adjustments are made to the throttling
during runtime based on changes in system cooling (fan speed).
Intel® Server Systems supporting the Intel® Xeon® processor E5-2600 v3, v4 product family introduce a new
type of CLTT which is referred to as Hybrid CLTT for which the Integrated Memory Controller estimates the
DRAM temperature in between actual reads of the TSODs. Hybrid CLTT shall be used on all Intel® Server
Systems supporting the Intel® Xeon® processor E5-2600 v3, v4 product family that have DIMMs with thermal
sensors. Therefore, the terms Dynamic-CLTT and Static-CLTT are really referring to this ‘hybrid’ mode. Note
that if the IMC’s polling of the TSODs is interrupted, the temperature readings that the BMC gets from the
IMC shall be these estimated values.
7.3.14.6.3 DIMM Temperature Sensor Input to Fan Speed Control
A clamp algorithm is used for controlling fan speed based on DIMM temperatures. Aggregate DIMM
temperature margin sensors are used as the control input to the algorithm.
7.3.14.6.4 Dynamic (Hybrid) CLTT
The system will support dynamic (memory) CLTT for which the BMC FW dynamically modifies thermal offset
registers in the IMC during runtime based on changes in system cooling (fan speed). For static CLTT, a fixed
offset value is applied to the TSOD reading to get the die temperature; however this is does not provide
results as accurate when the offset takes into account the current airflow over the DIMM, as is done with
dynamic CLTT.
In order to support this feature, the BMC FW will derive the air velocity for each fan domain based on the
PWM value being driven for the domain. Since this relationship is dependent on the chassis configuration, a
method must be used which supports this dependency (for example, through OEM SDR) that establishes a
lookup table providing this relationship.
BIOS will have an embedded lookup table that provides thermal offset values for each DIMM type and air
velocity range (3 ranges of air velocity are supported). During system boot BIOS will provide 3 offset values
(corresponding to the 3 air velocity ranges) to the BMC for each enabled DIMM. Using this data the BMC FW
constructs a table that maps the offset value corresponding to a given air velocity range for each DIMM.
During runtime the BMC applies an averaging algorithm to determine the target offset value corresponding
to the current air velocity and then the BMC writes this new offset value into the IMC thermal offset register
for the DIMM.
7.3.14.6.5 Autoprofile
The server board implemented autoprofile feature to improve upon previous platform configuration-
dependent FSC and maintain competitive acoustics within the market. This feature is not available for third
party customization.