Cisco UCS C220 M4

3-18
Cisco UCS C220 M4 Server Installation and Service Guide
OL-32473-01
Chapter 3 Maintaining the Server
Installing or Replacing Server Components
Replacing DIMMs
This section includes the following topics:
• Memory Performance Guidelines and Population Rules, page 3-18
• DIMM Replacement Procedure, page 3-21
Caution DIMMs and their sockets are fragile and must be handled with care to avoid damage during installation.
Caution Cisco does not support third-party DIMMs. Using non-Cisco DIMMs in the server might result in system
problems or damage to the motherboard.
Note To ensure the best server performance, it is important that you are familiar with memory performance
guidelines and population rules before you install or replace DIMMs.
Memory Performance Guidelines and Population Rules
This section describes the type of memory that the server requires and its effect on performance. The
section includes the following topics:
• DIMM Slot Numbering, page 3-18
• DIMM Population Rules, page 3-19
• Memory Mirroring and RAS, page 3-20
• Lockstep Channel Mode, page 3-20
DIMM Slot Numbering
Figure 3-12 shows the numbering of the DIMM slots.
Figure 3-12 DIMM Slots and CPUs
Front of Server
CPU 2
CPU 1
B3
B2
B1
A3 A2
A1
C1
C2
C3
D1
D2
D3
F3 F2 F1
E3
E2 E1
G1 G2
G3
H1
H2
H3
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