Thermal Configuration "Increased Cooling" BIOS Option

[chuckk281]

John had a customer question regarding thermal cooling options:

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My customer deploys C7000s with BL460c Gen8s loaded with E5-2680s and 16*16GB DIMMs.

They used default Thermal Cooling level of “Optimal”

They’ve been getting some temp warnings and messages about lowering clock speed (didn’t send a copy.)

They want to know what happens with the chassis if they change the BIOS setting to “Increased Cooling”

They are somewhat CFM sensitive. 

Any help or pointers appreciated.

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Input from Monty:

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The Onboard Administrator thermal logic for server blades uses the iLO Virtual Fan sensor to control the fans in the zone including that server blade.

The iLO Virtual Fan sensor value is computed based on an algorithm using “Sea of Sensor” readings and tables provided by the BIOS ROM for that server blade.

Changing the BIOS setting for cooling will change the thermal table used by the iLO.  The name “Increased Cooling” sounds like it will change the tables to increase the Virtual Fan value for a given set of sea of sensors temperature readings.

This will likely cause the OA to increase the speed of the enclosure fans in that zone.

But since the c-Class thermal logic is a closed loop system – we cannot predict the change to the enclosure fans, Your customer should be able to characterize the impact by running their workload on the servers before and after they change the BIOS thermal setting.

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Any other input or suggestions?