Memory Module Installation Rules And Order; Memory Guidelines - Lenovo ThinkSystem SR950 Setup Manual

• When handling a device, carefully hold it by the edges or the frame.
• Do not touch solder joints, pins, or exposed circuitry.
• Keep the device from others' reach to prevent possible damages.

Memory module installation rules and order

Memory modules must be installed in a specific order based on the memory configuration that you
implement and the number of processors and memory modules installed in the server.
The following memory configurations and population sequences are supported for the ThinkSystem SR950
server:
• "Independent memory mode" on page 63
– "Installation order: independent memory mode with two processors" on page 64
– "Installation order: independent memory mode with three processors" on page 65
– "Installation order: independent memory mode with four processors" on page 69
– "Installation order: independent memory mode with six processors" on page 73
– "Installation order: independent memory mode with eight processors" on page 83
• "Memory mirroring" on page 100
– "Installation order: memory mirroring with two processors" on page 101
– "Installation order: memory mirroring with three processors" on page 102
– "Installation order: memory mirroring with four processors" on page 106
– "Installation order: memory mirroring with six processors" on page 110
– "Installation order: memory mirroring with eight processors" on page 122
• "Memory sparing" on page 139
– "Installation order: memory sparing with two processors" on page 140
– "Installation order: memory sparing with three processors" on page 141
– "Installation order: memory sparing with four processors" on page 145
– "Installation order: memory sparing with six processors" on page 149
– "Installation order: memory sparing with eight processors" on page 161
For information about criteria that must be followed when selecting and installing memory modules in your
server, see "Memory guidelines" on page 58.
For information about configuring memory settings, see "Memory configuration" in the ThinkSystem SR950
Setup Guide.

Memory guidelines

There are a number of criteria that must be followed when selecting and installing memory modules in your
server.
The DIMM population sequences in this document show all memory population combinations that are
supported by your server. Some of these combinations will perform better than others because they balance
the distribution of memory across processors, memory controllers, and memory channels. Balanced memory
configurations enable optimal interleaving across all populated memory channels of a processor to boost
memory performance.
See the
"Install a memory module (option)" in the ThinkSystem SR950 Setup Guide
about installing and removing memory. This guide will help with memory selection and planning. More
information about optimizing memory performance and configuring memory is available at the Lenovo Press
website:
https://lenovopress.com/servers/options/memory
ThinkSystem SR950 Setup Guide
58
for important information