Datasheet

Intel® Server Board S2600CW Platform Management Intel® Server Board S2600CW Family TPS
80 Revision1.11
The following terminology is used for the various memory throttling options:
 Static Open Loop Thermal Throttling (Static-OLTT): OLTT control registers are
configured by BIOS MRC remain fixed after post. The system does not change any of
the throttling control registers in the embedded memory controller during runtime.
 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 Open Loop Thermal Throttling (Dynamic-OLTT): OLTT control registers are
configured by BIOS MRC during POST. Adjustments are made to the throttling during
runtime based on changes in system cooling (fan speed).
 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 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 CLTTT shall be used on all Intel® Server Systems supporting the Intel® Xeon® processor
E5-2600 v3 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.
5.3.14.6.3 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.
5.3.14.6.4 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 does not provide as accurate results as 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.