Replacing Dimms - Cisco APIC M3 Installation And Service Manual

Maintaining the Server
• The maximum combined memory allowed in the 12 DIMM slots controlled by any one CPU is 768 GB.
• Memory mirroring reduces the amount of memory available by 50 percent because only one of the two
• The NVIDIA Tesla P-Series GPU can support more than 1 TB of memory in the server. All other NVIDIA
• Observe the DIMM mixing rules shown in the following table.
Memory Mirroring
The CPUs in the server support memory mirroring only when an even number of channels are populated with
DIMMs. If one or three channels are populated with DIMMs, memory mirroring is automatically disabled.
Memory mirroring reduces the amount of memory available by 50 percent because only one of the two
populated channels provides data. The second, duplicate channel provides redundancy.

Replacing DIMMs

Identifying a Faulty DIMM
Each DIMM socket has a corresponding DIMM fault LED, directly in front of the DIMM socket. See
Diagnostic LEDs, on page 27
these LEDs light amber to indicate a faulty DIMM.
Step 1
Remove an existing DIMM:
a) Shut down and remove power from the server as described in
on page 29.
12 (A1, B1); (C1, D1);
(E1, F1)
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.
populated channels provides data. When memory mirroring is enabled, you must install DIMMs in even
numbers of channels.
GPUs (M-Series) can support only 1 TB or less of memory in the server.
Table 5: DIMM Mixing Rules
DIMM Parameter
DIMM Capacity
For example, 8GB, 16GB,
32GB, 64GB, 128GB
DIMM speed
For example, 2666 GHz
DIMM type
RDIMMs or LRDIMMs
for the locations of these LEDs. When the server is in standby power mode,
(A2, B2); (C2, D2);
(E2, F2)
DIMMs in the Same Channel
You can mix different capacity
DIMMs in the same channel (for
example, A1, A2).
You can mix speeds, but DIMMs
will run at the speed of the slowest
DIMMs/CPUs installed in the
channel.
You cannot mix DIMM types in a
channel.
Shutting Down and Removing Power From the Server,
Cisco APIC M3/L3 Server Installation and Service Guide
Replacing DIMMs
(G1, H1); (J1, K1); (G2, H2); (J2, K2);
(L1, M1) (L2, M2)
DIMMs in the Same Bank
You cannot mix DIMM capacities in
a bank (for example A1, B1). Pairs of
DIMMs must be identical (same PID
and revision).
You cannot mix DIMM speeds in a
bank (for example A1, B1). Pairs of
DIMMs must be identical (same PID
and revision).
You cannot mix DIMM types in a
bank.
Internal
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