The table below lists recommended configurations. Using 5, 6, 7, 9, 10, or 11
DIMMs per CPU is not recommended.
Note
The CPU numbering in the lower CPU module 1 is CPU 1 and CPU 2; in the
upper CPU module 2, the system numbers the CPUs as CPU 3 and CPU 4. The
channel lettering is the same in both CPU modules. Balance the DIMMs evenly
across all four CPUs, if present.
Note
Table 6: DIMM Population Order
Populate CPU 2 or CPU 4 Slots
Populate CPU 1 or CPU 3 Slot
Number of
DIMMs per CPU
(Recommended
Configurations)
Black #2 Slots
Blue #1 Slots
Black #2 Slots
Blue #1 Slots
-
(G1)
-
(A1)
1
-
(G1, H1)
-
(A1, B1)
2
-
(G1, H1, J1)
-
(A1, B1, C1)
3
-
(G1, H1); (K1, L1)
-
(A1, B1); (D1, E1)
4
(G2, H2); (K2, L2)
(G1, H1); (K1, L1)
(A2, B2); (D2, E2)
(A1, B1); (D1, E1)
8
(G2, H2); (J2, K2);
(L2, M2)
(G1, H1); (J1, K1);
(L1, M1)
(A2, B2); (C2, D2);
(E2, F2)
(A1, B1); (C1, D1);
(E1, F1)
12
• The maximum combined memory allowed in the 12 DIMM slots controlled by any one CPU is 768 GB.
To populate the 12 DIMM slots with more than 768 GB of combined memory, you must use a
high-memory CPU that has a PID that ends with an "M", for example, UCS-CPU-6134M.
• All DIMMs must be DDR4 DIMMs that support ECC. Non-buffered UDIMMs and non-ECC DIMMs
are not supported.
• Memory mirroring reduces the amount of memory available by 50 percent because only one of the two
populated channels provides data. When memory mirroring is enabled, you must install DIMMs in even
numbers of channels.
• NVIDIA M-Series GPUs can support only less-than 1 TB memory in the server.
• NVIDIA P-Series GPUs can support 1 TB or more memory in the server.
• AMD FirePro S7150 X2 GPUs can support only less-than 1 TB memory in the server.
• Observe the DIMM mixing rules shown in the following table.
Table 7: DIMM Mixing Rules
DIMMs in the Same Bank
DIMMs in the Same Channel
DIMM Parameter
Cisco UCS C480 M5 Server Installation and Service Guide
109
Maintaining the Server
DIMM Population Rules and Memory Performance Guidelines
