The following memory protection technologies are supported:
ECC
Chipkill (for x4-based memory DIMMs)
Memory mirroring
Memory rank sparing
Chipkill works only in independent channel mode (the default operational mode) and supports only x4-based
memory DIMMs.
If memory mirroring is used, then DIMMs must be installed in pairs (a minimum of one pair per
each processor), and both DIMMs in a pair must be identical in type and size.
If memory rank sparing is used, then a minimum of one quad-rank DIMM or two single-rank or dual-rank
DIMMs must be installed per populated channel (the DIMMs do not need being identical). In rank sparing
mode, one rank of a DIMM in each populated channel is reserved as spare memory. The size of a rank varies
depending on the DIMMs installed.
Chipkill, memory mirroring, and memory rank sparing modes are mutually exclusive. Only one operational
memory mode can be enabled on a server, and it is a system-wide setting.
System x engineering tested and validated system designs that support memory speeds beyond Intel memory
specifications, which provides benefits for workloads that require memory speed and density.
System x TruDDR4 memory is fully supported up to the speeds that are shown in the following tables. Table
cells highlighted with a gray background indicate when the DIMMs are allowed to operate at a higher speed
than Intel specifications define.
Table 7. System x3550 M5 maximum memory speeds and capacities
DIMMs per channel
RDIMM
LR-DIMM
Memory bus speed
Maximum capacity*
Memory bus speed
Maximum capacity*
Intel Xeon processor E5-2600 v4 product family
1 DPC
2400 MHz
256 GB (8x 32 GB)
2400 MHz
512 GB (8x 64 GB)
2 DPC
2400 MHz
512 GB (16x 32 GB)
2400 MHz
1,024 GB (16x 64 GB)
3 DPC
1866 MHz
768 GB (24x 32 GB)
2133 MHz
1,536 GB (24x 64 GB)
Intel Xeon processor E5-2600 v3 product family
1 DPC
2133 MHz
256 GB (8x 32 GB)
2133 MHz
512 GB (8x 64 GB)
2 DPC
2133 MHz
512 GB (16x 32 GB)
2133 MHz
1,024 GB (16x 64 GB)
3 DPC
1866 MHz
768 GB (24x 32 GB)
1866 MHz
1,536 GB (24x 64 GB)
* Maximum memory capacity is achieved with two processors installed. With one processor, the maximum memory capacity is a
half of what is shown.
Lenovo System x3550 M5 (Machine Type 8869)
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