v The server supports 1.35-volt (low-voltage) registered DIMMs and 1.5-volt
(standard voltage) registered DIMMs as follows:
– Supported DIMMs with speeds of 1333 MHz or less support both 1.35 V and
1.5 V operation, depending on the configuration settings in the Setup utility.
– Supported DIMMs with speeds of 1600 MHz do not support 1.35 V operation.
Only 1.5 V operation is supported.
v Single-device data correction (SDDC) support is available only when 16 GB or 32
GB x4 DRAM technology DIMMs are installed in the server.
v The following table provides information about the maximum amount of
memory that the server can support when you fully populate the server and the
optional microprocessor and memory expansion tray by using the supported
DIMMs.
Table 6. The maximum amount of memory that the server can support
Number of DIMM connectors Maximum memory
24 DIMMs on system board Up to 768 GB
24 DIMMs on the optional microprocessor
and memory expansion tray
Up to 768 GB
Total = 1.5 TB of memory
Note: The server can support a maximum 1.5 TB of system memory when the server is
fully populated with 32 GB DIMMs and the optional microprocessor and memory
expansion tray is installed and fully populated with 32 GB DIMMs.
v The DIMM options that are available for the server are 4 GB, 8 GB, 16 GB, 32
GB.
v The server system board supports a minimum of 4 GB and a maximum of 768
GB of system memory. However, the server can support an additional 768 GB of
memory when an optional microprocessor and memory expansion tray is
installed in the server, for a total of 1.5 TB of system memory, depending on the
model.
Note: The amount of usable memory is reduced, depending on the system
configuration. A certain amount of memory must be reserved for system
resources. To view the total amount of installed memory and the amount of
configured memory, run the Setup utility. For additional information, see
“Configuring the server” on page 138.
v The server system board provides four memory channels for each
microprocessor, and each memory channel supports up to three DIMMs. The
optional microprocessor and memory expansion tray also provides four memory
channels that support up to three DIMMs per channel. The following illustration
shows the memory channels for each microprocessor.
The following table lists the DIMM connectors on each memory channel for the
microprocessors on the system board and the optional expansion tray.
44 System x3750 M4 Types 8722 and 8733: Installation and Service Guide