Lenovo x3755 M3 Product Manual page 9

The System x3755 M3 supports up to 16 DIMMs when two processors are installed and up to 32 DIMMs
when four processors are installed. Each processor has four memory channels, and there are two DIMMs
per channel.
The following rules apply when selecting the memory configuration:
All configurations support RDIMMs

Models with AMD Opteron 6200 processors also support UDIMMs

Mixing different types of memory (UDIMMs and RDIMMs) is not supported.

Mixing 1.5 V and 1.35 V DIMMs is supported, except in CTO configurations built in the factory. If 1.5

V and 1.35 V DIMMs are mixed, all DIMMs operate at 1.5 V
Minimum of 2 DIMMs must be installed per processor

The maximum quantity of DIMMs that can be installed in the server depends on the number of CPUs,

DIMM type, rank, and operating voltage, as shown in the "Max. qty supported" row in the following
table.
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 CPU.

Lowest of maximum operating speeds for selected memory configuration that depends on rated

speed, operating voltage, and quantity of DIMMs per channel, as shown under "Maximum
operating speed" section in the table.
The following two tables show the characteristics of the supported DIMMs. Table 6 is for models with
AMD Opteron 6300 processors and Table 7 is for models with AMD Opteron 6200 processors. Tables
cells highlighted with a gray background indicate when the combination of DIMM voltage and the number
of DIMMs per channel still allows the DIMMs to operate at a rated speed.
The following memory protection technologies are supported:
ECC

ChipKill (for x4 and x8-based DIMMs)

Memory sparing

Note: Memory Sparing is not supported with quad-rank DIMMs.
System x3755 M3 9