Memory Options - Lenovo System x3650 M5 Product Manual

Memory options

The System x3650 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 has a unique signature programmed into the DIMM that enables System x
servers to verify whether the memory installed is qualified or 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; there are three DIMMs per channel.
The following rules apply when selecting the memory configuration:
The server supports RDIMMs and LRDIMMs.

Mixing 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 these:

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" section 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 is operational mode) and supports only
x4-based memory DIMMs.
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