Dell PowerEdge T320 Technical Manual page 22

Feature
Memory thermal
throttling
For information on memory mirroring and sparing configurations, see the
Systems Owner's Manual
22 PowerEdge T320 Technical Guide
Description
errors occur in a rank or channel, it is moved to the spare area while the operating
system is running to prevent the error from causing an uncorrectable failure.
This feature helps to optimize power/performance and can also be used to
prevent DIMMs from overheating.
on Dell.com/Support/Manuals.
Dell PowerEdge T320