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Oracle® Server X5-2 Service Manual

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Updated: January 2018
 
 

Populating DIMMs for Optimal System Performance

Optimal performance is achieved by populating the DIMMs so that the memory is symmetrical, or balanced. Symmetry is achieved by adhering to the following guidelines:

  • In single-processor systems, populate DIMMs of the same size in multiples of four.

  • In dual-processor systems. populate DIMMs of the same size in multiples of eight.

  • Populate the DIMM sockets in the order described in the following sections.

The following sections provide an example of how to populate the DIMM sockets to achieve optimal system performance.


Note -  Not all possible configurations are shown here.

Populating DIMMs in Single-Processor Systems for Optimal System Performance

In single-processor systems, install DIMMs only into DIMM sockets associated with processor 0 (P0). Starting with socket P0 D0. Fill the black sockets first, then the black sockets with white tabs, and then the white sockets, as shown in the following figure. Notice that the order of populating the black sockets is Ch C first, Ch A second, Ch D third, and Ch B last. Repeat the same population sequence for the black sockets with white tabs, and finally for the white sockets.

Figure 3  DIMM Population Order for Single-Processor Systems

image:Figure showing the DIMM population order for single-processor                                 systems.

The following table describes the proper order in which to populate DIMMs in a single-processor system using the numbered callouts in the above figure, the memory channel labels (Ch A through Ch D), and the DIMM socket labels (D0 through D11).

Table 12  DIMM Population Order for Single-Processor Systems
Population Order
DIMMs Sockets for Processor 0 (P0)
Memory Channels
Fill the black sockets first
First
D0
Ch C
Second
D11
Ch A
Third
D3
Ch D
Fourth
D8
Ch B
Then fill the black sockets with white tabs
Fifth
D1
Ch C
Sixth
D10
Ch A
Seventh
D4
Ch D
Eighth
D7
Ch B
Then fill the white sockets
Ninth
D2
Ch C
Tenth
D9
Ch A
Eleventh
D5
Ch D
Twelfth
D6
Ch B

Populating DIMMs in Dual-Processor Systems for Optimal System Performance

In dual-processor systems, populate DIMMs into DIMM sockets starting with processor 0 (P0) D0, then, alternating between sockets associated with processor 0 (P0) and matching sockets for processor 1 (P1). Fill the black sockets first, then the black sockets with white tabs, and then the white sockets, as shown in the following figure. Notice that the order of populating the black DIMM sockets is Ch C first, Ch A second, Ch D third, and Ch B last. Repeat the same population sequence for the black sockets with white tabs, and finally, for the white sockets.

Figure 4  DIMM Population Order for Dual-Processor Systems

image:Figure showing the DIMM population order for dual-processor                                 systems

The following table describes the proper order in which to install DIMMs in a dual-processor system using the numbered callouts in the above figure, the memory channels labels (Ch A through Ch D), and the DIMM socket labels (D0 through D11).

Table 13  DIMM Population Order for Dual-Processor Systems
Population Order
DIMM Sockets for Processor 0 (P0)
DIMM Sockets for Processor 1 (P1)
Memory Channels
Fill the black sockets first
Alternate between processor 0...
...and processor 1
First
Fill D0 first
Then fill D0
Ch C
Second
Fill D11 first
Then fill D11
Ch A
Third
Fill D3 first
Then fill D3
Ch D
Fourth
Fill D8 first
Then fill D8
Ch B
Fill the black sockets with white tabs
Alternate between processor 0...
...and processor 1
Fifth
Fill D1 first
Then fill D1
Ch C
Sixth
Fill D10 first
Then fill D10
Ch A
Seventh
Fill D4 first
Then fill D4
Ch D
Eighth
Fill D7 first
Then fill D7
Ch B
Fill the white sockets last
Alternate between processor 0...
...and processor 1
Ninth
Fill D2 first
Then fill D2
Ch C
Tenth
Fill D9 first
Then fill D9
Ch A
Eleventh
Fill D5 first
Then fill D5
Ch D
Twelfth
Fill D6 first
Then fill D6
Ch B