Specifications

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3-17
Cisco UCS C200 Server Installation and Service Guide
OL-20732-02
Chapter 3 Maintaining the Server
Installing or Replacing Components
Memory Population Rules
When considering the memory configuration of your server, you should consider the following items:
• DIMMs within the server should all be the same type, speed, and size. Do not mix different size
DIMMs or DIMMs with different clock rates in the same server. Doing so causes the system to set
the memory system speed to that of the slowest installed DIMMs.
• DIMMs can be used either in a one DIMM per Channel (1DPC) configuration or in a two DIMMs
per Channel (2DPC) configuration.
• There are blue and black DIMM slots. Populate blue slots in a bank first.
Memory Mirroring and RAS
• The CPUs support memory mirroring only when Channels A and B on CPU 1 are populated with
DIMMs that are identical in configuration, size, and speed. Do not populate channel C. If three
channels are populated with DIMMs, memory mirroring is automatically disabled.
• If DIMMs on CPU 2 are populated, channels D and E must be populated with DIMMs that are
identical in configuration, size, and speed. Do not populate channel F. If three channels are
populated with DIMMs, memory mirroring is automatically disabled.
• If memory mirroring is used, the DRAM size is reduced by 50 percent for reasons of reliability.
Memory sparing is not supported.
DIMM Installation Procedure
To install or replace a DIMM, follow these steps:
Note Refer to the DIMM population rules before removing or installing DIMMs. See the “Memory
Performance Guidelines and Population Rules” section on page 3-15.
Step 1 Remove an existing DIMM:
a. Power off the server as described in the “Shutting Down and Powering Off the Server” section on
page 3-6.
b. Disconnect all power cords from the power supplies.
c. Slide the server out the front of the rack far enough so that you can remove the top cover. You might
have to detach cables from the rear panel to provide clearance.
Caution If you cannot safely view and access the component, remove the server from the rack.
d. Remove the top cover as described in the “Removing and Replacing the Server Top Cover” section
on page 3-8.
e. Remove the air baffle that sits over the CPUs and DIMMs and set it aside.
f. Push down on the ejector levers at both ends of the DIMM slot.
g. Grasp the DIMM by its top corners and remove it from the server. Place the DIMM on an antistatic
mat or in antistatic packaging.