Memory Options - Lenovo System x3550 M5 Product Manual

Memory options

System x3550 M5 supports TruDDR4 Memory. TruDDR Memory uses the highest-quality components
sourced from Tier 1 DRAM suppliers and only memory that meets our strict requirements is selected. It is
compatibility tested and tuned on every System x server to maximize performance and reliability. TruDDR4
Memory will have a unique signature programmed into the DIMM, which will enable System x servers to
verify whether the memory installed is qualified/supported. Because TruDDR4 Memory is authenticated,
certain extended memory performance features can be enabled to extend performance over industry
standards. From a service and support standpoint, System x memory automatically assumes the system's
warranty, and service and support provided worldwide.
The server supports up to 12 DIMMs when one processor is installed and up to 24 DIMMs when two
processors are installed. Each processor has four memory channels, and there are three DIMMs per
channel.
The following rules apply when selecting the memory configuration:
The server supports RDIMMs and LRDIMMs.
Mixing different types of memory (RDIMMs and LRDIMMs) is not supported.
The maximum quantity of DIMMs that can be installed in the server depends on the number of
processors.
All DIMMs in the server operate at the same speed, which is determined as the lowest value of the
following speeds:
Memory speed that is supported by the specific processor.
Lowest of maximum operating speeds for selected memory configuration that depends on
quantity of DIMMs per channel, as shown under "Maximum operating speed" in Table 5.
The following memory protection technologies are supported:
ECC
Chipkill (for x4-based memory DIMMs)
Chipkill works only in independent channel mode (the default operational mode) and supports only x4-
based memory DIMMs.
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