Cisco UCS C480 M5 Installation And Service Manual page 110

DIMM Population Rules and Memory Performance Guidelines
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.
DIMM Population Rules and Memory Performance Guidelines
This topic describes the rules and guidelines for maximum memory performance.
Note
You must use DIMM blanking panels in any DIMM slots that do not have DIMMs installed to ensure adequate
air flow.
DIMM Slot Numbering
The following figure shows the numbering of the DIMM slots on the CPU module board. When a CPU module
is in bay 1 (the lower bay), the system numbers the CPUs as CPU 1 and CPU 2. When a CPU module is in
bay 2 (the upper bay), the system numbers the CPUs as CPU 3 and CPU 4.
Figure 53: DIMM Slot Numbering
DIMM Population Rules
Observe the following guidelines when installing or replacing DIMMs for maximum performance:
• Each CPU supports six memory channels.
• Each channel has two DIMM sockets (for example, channel A = slots A1, A2).
• For optimal performance, populate DIMMs in the order shown in the following table, depending on the
Cisco UCS C480 M5 Server Installation and Service Guide
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• CPU 1/3 supports channels A, B, C, D, E, F.
• CPU 2/4 supports channels G, H, J, K, L, M.
number of DIMMs per CPU. Balance DIMMs evenly across the two CPUs as shown in the table.
Maintaining the Server