IBM 7940, Problem Determination And Service Manual

Page: 58 / 160

2. Turn off the server and peripheral devices and disconnect all power cords and
external cables; then, remove the server from the rack.
3. Remove the server cover (see “Removing the cover” on page 31).
4. Open the retaining clip on each end of the DIMM connector.
Attention: To avoid breaking the retaining clips or damaging the DIMM
connectors, open and close the clips gently.
5. Lift the DIMM out of the connector.
6. If you are instructed to return the DIMM, follow all packaging instructions, and
use any packaging materials for shipping that are supplied to you.
Installing a memory module
For information about the types of dual inline memory modules (DIMMs) that the
server supports and other information that you must consider when installing
DIMMs, see the
User’s Guide on the IBM System x Documentation CD.
To optimize system performance in a single-microprocessor or dual-microprocessor
configuration, install DIMMs in the following sequence. Do not install DIMMs in
connectors 7 through 12 if microprocessor socket 2 (system-board identifier CPU2)
is empty.
Table 6. DIMM installation sequence
Number of DIMMs
installed
DIMM connector population with
one microprocessor installed
DIMM connector population with
two microprocessors installed
2 1, 2 1, 2
4 1, 2, 3, 4 1, 2, 7, 8
6 1, 2, 3, 4, 5, 6 1, 2, 3, 4, 7, 8
8 Not supported 1, 2, 3, 4, 7, 8, 9, 10
10 Not supported 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
12 Not supported 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
The following illustration shows the DIMM slots (memory connectors) on the system
board.
40
IBM System x3455 Type 7940 and 7941: Problem Determination and Service Guide