Lenovo ThinkServer RD540 70AR, User Manual And Hardware Maintenance Manual

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The following table explains the memory module installation rules for servers that have only one
microprocessor (CPU1) installed. The “X” mark indicates the memory slots into which the memory modules
should be installed in different situations.
Notes:
• All memory modules to be installed on a server must be the same type.
• When you install memory modules with different ranks in one channel, start from the farthest memory slot
in the channel and install the memory module that has the most ranks first.
• When 1.35 V memory modules and 1.50 V memory modules are installed into the memory slots for the
same microprocessor, all the memory modules run at 1.50 V.
• When memory modules with different frequencies are installed into the memory slots for the same
microprocessor, all the memory modules run at the lowest frequency.
• It is recommended that you install the high-frequency memory modules into the memory slots for the
same microprocessor to ensure high performance.
Figure 41. CPU1 DIMMs
Table 3. Memory module installation rules for servers with one microprocessor
CPU1 DIMM A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3
One DIMM X
Two DIMMs X X
Three DIMMs X X X
Four DIMMs X X X X
Six DIMMs X X X X X X
Eight DIMMs X X X X X X X X
Twelve DIMMs X X X X X X X X X X X X
Note: The 12 DIMMs configuration is supported only when you are using normal RDIMMs.
The following table explains the memory module installation rules for servers that have two microprocessors
(CPU1 and CPU2) installed. The “X” mark indicates the memory slots into which the memory modules
should be installed in different situations.
Chapter 6
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Installing, removing, or replacing hardware
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