Cisco UCS C250, Инструкция по установке и обслуживанию

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Cisco UCS C250 Server Installation and Service Guide
OL-20888-02
Chapter 3 Maintaining the Server
Installing or Replacing Components
Memory Population Rules and Supported Configurations
This server uses Cisco extended memory technology. To improve performance, write operations are made
simultaneously to both DIMMs of a matched pair. When considering the memory configuration of your server,
consider the following items:
• Refer to Table 3-3 on page 3-22 for the supported DIMM configurations and the total memory for each.
•
Refer to Table 3-4 on page 3-23 for the order in which DIMM pairs must be populated for each supported
configuration. Find the column for the number of DIMMs in your configuration, then read down the
column to see which DIMM slots on each CPU must be populated for that configuration. Also see
Figure 3-12 on page 3-20 for DIMM slot positions.
• Both DIMMs of a pair must be installed side-by-side, under the same CPU, in matching color DIMM
sockets.
For example, to add DIMM pairs to go from a a 16-DIMM configuration to a 20-DIMM configuration,
refer to
Table 3-4 on page 3-23 . As the differences between the columns for the 16-DIMM and 20-DIMM
configurations indicate, you add one DIMM pair to slots B4 and B5 under CPU1 and one DIMM pair to
slots E4 and E5 under CPU2.
As shown in Figure 3-12 on page 3-20 , B4 and B5 are side-by-side blue slots controlled by CPU1; E4 and
E5 are side-by-side blue slots controlled by CPU2.
•
The two DIMMs within a DIMM pair must have the identical manufacturer, type, speed, and size. Cisco
provides spare DIMMs for this product in matched pair kits.
• We recommend you do not mix different sized DIMMs or DIMMs with different clock rates in the same
server. This causes the memory system to operate at the speed of the slowest DIMMs that are installed.
•
(Generation M2 only) Low-voltage (1.35 V) DIMM pairs and standard-voltage DIMM pairs (1.5 V) can
be mixed in the same server. Note that this causes the system BIOS to default to standard-voltage operation
(Performance Mode). See the
Low-Voltage DIMM Considerations (Generation M2 Only), page 3-23 .
Note
Low voltage DIMMs are supported in Generation M2 servers only.
1.
Refer to Table 3-3 , which summarizes the supported DIMM configurations.
2. Refer to Table 3-4 on page 3-23 for the slot population rules for each configuration, based on the total
number of DIMMs .
Note All Generation M2 server DIMM configurations require two CPUs to be installed in the server.