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
•
The two low-voltage 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.
• Low-voltage DIMM pairs and standard-voltage DIMM pairs can be mixed in the same server. Note
that this causes the system BIOS to default to standard-voltage operation (Performance Mode). That
is, the server cannot operate in Power Saving Mode unless all DIMM pairs in the server are
low-voltage DIMMs.
Note CPUs that have a maximum memory frequency less than 1333 MHz support LV DIMMs
operating in Power saving Mode only, and do not support Performance mode. However, if your
server has one of these CPUs, monitoring output for LV DIMMs will show identical voltages for
both Power Saving Mode and Performance Mode. In this case, Performance Mode is not active
and its fields only mirror the values from the Power Savings Mode fields.
• In Generation M2 only, there is a setting in the BIOS Setup utility that you can use to change the
DDR memory mode when the server has all low-voltage DIMMs installed. To access this setting,
follow these steps:
Step 1 Enter the BIOS setup utility by pressing the F2 key when prompted during bootup.
Step 2
Select the Advanced tab.
Step 3 Select Low Voltage DDR Mode .
Step 4
In the pop-up window, select either Power Saving Mode or Performance Mode .
•
Power Saving Mode–Enables low-voltage memory operation. This setting is available only if all
DIMMs installed are low-voltage DIMMs.
•
Performance Mode–Disables low-voltage memory operation. If you mix low-voltage DIMM pairs
with standard-voltage DIMM pairs, the system defaults to this setting.
Step 5 Press F10 to save your changes and exit the setup utility.