Memory
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.
All DIMMs in the server operate at the same speed, which is determined as the lowest value of:
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 is operational mode) and supports only x4-based
memory DIMMs.
The following table shows the characteristics of the supported DIMMs. Tables cells highlighted with a gray
background indicate when the number of DIMMs per channel still allows the DIMMs to operate at a rated
speed.
Table 5. Maximum memory speeds
DIMM specification
RDIMM
LRDIMM
Rank
Single rank
Dual rank
Quad rank
Part numbers
46W0784 (4 GB)
46W0788 (8 GB)
46W0792 (8 GB)
46W0796 (16 GB)
95Y4808 (32 GB)
46W0800 (32 GB)
95Y4812 (64 GB)
Rated speed
2133 MHz
2133 MHz
2133 MHz
2133 MHz
Rated voltage
1.2 V
1.2 V
1.2 V
1.2 V
Maximum quantity supported**
24
24
24
24
Maximum DIMM capacity
8 GB
8 GB
32 GB
64 GB
Maximum memory capacity
192 GB
192 GB
768 GB
1.5 TB
Maximum memory at rated speed
64 GB
64 GB
512 GB
1 TB
Maximum operating speed
1 DIMM per channel
2133 MHz
2133 MHz
2133 MHz
2133 MHz
2 DIMMs per channel
2133 MHz
2133 MHz
2133 MHz
2133 MHz
3 DIMMs per channel
1600 MHz
1600 MHz
1866 MHz
1866 MHz
** The maximum quantity that is supported is shown for two processors installed.
Lenovo System x3650 M5 (E5-2600 v3)
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