available when memory mirroring is enabled. Note that some Windows

operating systems do not recognize memory mirroring when they report the

amount of available memory and instead report the total DIMM capacity.

Toenable memory mirroring, you must install DIMMs in sets of four, one pair in

each memory card. All DIMMs in each set must be the same size and type.

Memory cards 1 and 2 mirror each other,cards 3 and 4 mirror each other,

memory cards 5 and 6 mirror each other,and cards 7 and 8 mirror each other.

Install DIMMs in the sequence shown in the following table.

Table9. Memory-card installation sequence for memory-mirroring configuration
DIMM quad installation
order Memory card Connector numbers
First 1 1 and 8
2 1 and 8
Second 7 1 and 8
8 1 and 8
Third 3 1 and 8
4 1 and 8
Fourth 5 1 and 8
6 1 and 8
Fifth 1 3and 6
2 3 and 6
Sixth 7 3 and 6
8 3 and 6
Seventh 3 3 and 6
4 3 and 6
Eighth 5 3 and 6
6 3 and 6
Ninth 1 2and 7
2 2 and 7
Tenth 7 2and 7
8 2 and 7
Eleventh 3 2 and 7
4 2 and 7
Twelfth 5 2 and 7
6 2 and 7
Thirteenth 1 4 and 5
2 4 and 5
Fourteenth 7 4and 5
8 4 and 5
Fifteenth 3 4 and 5
4 4 and 5
Sixteenth 5 4and 5
6 4 and 5
68 IBM System x3850 X5 and x3950 X5 Types7145, 7146, 7143, and 7191: Installation and User's Guide