Intel S5000XAL User Manual

 

The minimum memory upgrade increment is two DIMMs per branch. The DIMMs must cover the same 
slot position on both channels. DIMMs pairs must be identical with respect to size, speed, and 
organization. DIMMs that cover adjacent slot positions do not need to be identical. 

When adding two DIMMs to the configuration shown in Figure 12, the DIMMs should be populated in 
DIMM slots C1 and D1 as shown in the following diagram.  Populated DIMM slots are shown in Grey. 

TP02301

DIMM D2

DIMM D1

DIMM C2

DIMM C1

DIMM B2

DIMM B1

DIMM A2

DIMM A1

Branch 0

MCH

Channel A

Channel B

Channel D

Channel C

Branch 1

 

Functionally, DIMM slots A2 and B2 could also have been populated instead of DIMM slots C1 and D1. 
However, your system will not achieve equivalent performance. Figure 13 shows the supported DIMM 
configuration that is recommended because it allows both memory branches from the MCH to operate 
independently and simultaneously. FBD bandwidth is doubled when both branches operate in parallel. 

When operating in mirrored mode, both branches operate in lock step. In mirrored mode, branch 1 
contains a replicate copy of the data in branch 0.  The minimum DIMM configuration to support memory 
mirroring is four DIMMs, populated as shown in Figure 13 above. All four DIMMs must be identical with 
respect to size, speed, and organization.  

To upgrade a four DIMM mirrored memory configuration, four additional DIMMs must be added to the 
system. All four DIMMs in the second set must be identical to the first with the exception of speed. The 
MCH will adjust to the lowest speed DIMM.