Dell PowerEdge M420 Owner's Manual page 44

Memory bus operating frequency can be 1600 MT/s or 1333 MT/s depending on:
• DIMM configuration (number of ranks)
• maximum frequency of the DIMMs
• DIMM operating voltage
• system profile selected (for example, Performance Optimized, Custom, or Dense Configuration Optimized)
• maximum supported DIMM frequency of the processors
The following table shows the memory populations and operating frequencies for the supported configurations.
DIMM Type DIMMs Populated/
Channel
RDIMM 1
RDIMM 1
The system contains six memory sockets split into two sets of three sockets, one set per processor. Each three-socket
set is organized into three channels.
NOTE: DIMMs in sockets A1 to A3 are assigned to processor 1 and DIMMs in sockets B1 to B3 are assigned to
processor 2.
Figure 19. Memory Socket Locations
Memory channels are organized as follows:
Processor 1
Processor 2
44
Operating Frequency (in MT/s)
1.5 V
1600 and 1333
-
channel 1: memory socket A1
channel 2: memory socket A2
channel 3: memory socket A3
channel 1: memory socket B1
channel 2: memory socket B2
channel 3: memory socket B3
Maximum DIMM Rank/
Channel
1.35 V
1333 Dual rank
1333 Quad rank