Symptoms
Memory slots on 14G PowerEdge Server can be populated differently than what is called out in the Installation and Service Manual.
NOTE: How to identify my server generation is explained in this Dell Knowledge Base article Dell PowerEdge servers by generation.
Resolution
NOTE: It is not advised to change the population of the memory.
If you have doubts, in a first step you can check if the server was ordered as "Performance Optimized". The following changes per system have resulted in greater system performance. The ISM for each system is being revised to reflect these updates. Here is a list of all changes per PowerEdge Server model:
Models R640, R740, R740XD, R940, R840, R940xa:
DIMM population changed when Performance Optimized Mode is ordered and there is a quantity of 4 or 8 DIMMs per CPU.
With DIMM quantity of 4 per CPU, the population is Slot 1, 2, 4, 5With DIMM quantity of 8 per CPU, the population is 1, 2, 4, 5, 7, 8, 10, 11.
Models FC640, M640, M640-VRTX, C4140, T640, DSS9600, DSS9620, DSS9630:
DIMM population changed when Performance Optimized Mode is ordered and there is a quantity of 4 and 8 DIMMs per CPU.
With DIMM quantity of 4 per CPU, the population is Slot 1, 2, 4, 5With DIMM quantity of 8 per CPU, the population is 1, 2, 4, 5, 7, 8, 10, 11 (2-2-2 platforms).
Models T440, R440, R540:
DIMM population changed when Performance Optimized Mode is ordered and there is a quantity of 4 and 8 DIMMs per CPU.
With DIMM quantity of 4 per CPU, the population is Slot 1, 2, 4, 5With DIMM quantity of 8 per CPU, the population is 1, 2, 4, 5, 7, 8, 9, 10.
Models C6420:
DIMM population changed when Performance Optimized Mode is ordered and there is a quantity of 4 DIMMs per CPU.
With DIMM quantity of 4 per CPU, the population is Slot 1, 2, 4, 5For 2-1-1 platforms, full population with 8 DIMMS has no sequence concerns
Models R6415, R7415, R7425 (AMD systems:
DIMM population changed when Performance Optimized Mode is ordered and there is a quantity of 4 or 8 DIMMs per CPU.
With DIMM quantity of 4, the population with 1 CPU is Slot 1, 3, 5, 7.
Dual CPU systems: CPU 2 population must match CPU 1 population.
With DIMM quantity of 8, the population with 1 CPU is slot 1, 2, 3, 4, 5, 6, 7, 8
Dual CPU systems: CPU 2 population must match CPU 1 population
