Kontron TIGH2U Carrier Grade Server - Manual (Page 42)

TIGH2U Server—Server Component Installations and Upgrades
Kontron Carrier Grade Server TIGH2U
Product Guide, rev.1.2 December 2009
42
3.4.2.5 Non-Mirrored Mode Memory Upgrades
The minimum memory upgrade increment is two DIMMs per branch. The DIMMs must cover the same
socket position on both channels. DIMM pairs must be identical with respect to size, speed, and
organization. DIMMs that cover adjacent socket positions do not need to be identical.
When adding two DIMMs to the configuration shown in Figure 23 , the DIMMs should be populated in
DIMM sockets C1 and D1 as shown in Figure 24 . Populated DIMM sockets are shown in grey.
Figure 24. Recommended Four-DIMM Configuration
Functionally, DIMM sockets A2 and B2 could also have been populated instead of DIMM sockets C1
and D1. However, the system will not achieve equivalent performance. Figure 24 shows the supported
DIMM configuration that is recommended because it allows both memory branches from the MCH to
operate independently and simultaneously. FBD bandwidth is doubled when both branches operate in
parallel.
3.4.2.6 Mirrored Mode Memory Configuration
When operating in mirrored mode, both branches operate in lock step. In mirrored mode, branch 1
contains a replica of the data in branch 0. The minimum DIMM configuration to support memory
mirroring is four DIMMs, populated as shown in Figure 24 . All four DIMMs must be identical with
respect to size, speed, and organization.
To upgrade a four DIMM mirrored memory configuration, four additional DIMMs must be added to the
system. All four DIMMs in the second set must be identical to the first with the exception of speed.
The MCH will adjust to the lowest speed DIMM.