Dell PowerEdge T430 Owner's Manual page 85

Figure 34. Memory socket locations
Memory channels are organized as follows:
Processor 1 channel 0: slots A1 and A5
channel 1: slots A2 and A6
channel 2: slots A3 and A7
channel 3: slots A4 and A8
Processor 2 channel 0: slot B1
channel 1: slot B2
channel 2: slot B3
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