IBM System x3650 M4 HD Product Manual page 11

The following rules apply when selecting the memory configuration:
The server supports UDIMMs, RDIMMs, and LRDIMMs.

Mixing different types of memory (UDIMMs, RDIMMs, and LRDIMMs) is not supported.

Mixing 1.5 V and 1.35 V DIMMs is supported; in such a case, all DIMMs operate at 1.5 V.

The maximum number of ranks per one channel is eight (except for Load Reduced DIMMs, where

more than eight ranks are supported, because one quad-rank LRDIMM provides the same electrical
load on a memory bus as a single-rank RDIMM).
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 Table 5.
All DIMMs in the server operate at the same speed, which is determined as the lowest value of the

following items:
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 the "Maximum
operating speed" section in Table 5.
The following table (Parts 1 and 2) shows the characteristics of the supported DIMMs. Tables cells that
are 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.
Table 5. Maximum memory speeds (Part 1: RDIMMs)
DIMM
specification
Rank
Part numbers
Rated speed
Rated voltage
Operating voltage
Max qty supported*
Max DIMM capacity
Max memory capacity
Max. memory
at rated speed
Maximum operating speed
1 DIMM per channel
2 DIMMs per channel
3 DIMMs per channel
* The maximum quantity that is supported is shown for two processors installed.
IBM System x3650 M4 HD
Single rank
00D5024 (4 GB)
00D5036 (8 GB)
1600 MHz
1.35 V
1.35 V 1.5 V
24 24
8 GB 8 GB
192 GB 192 GB
None 128 GB
1333 MHz 1600 MHz
1333 MHz 1600 MHz
800 MHz 1066 MHz
RDIMM
00D5020 (4 GB) 00D5044 (8 GB)
00D5032 (8 GB) 46W0672 (16 GB)
1866 MHz 1600 MHz
1.5 V
1.5 V 1.35 V
24 24
8 GB 16 GB
192 GB 384 GB
64 GB None
1866 MHz 1333 MHz
1600 MHz 1333 MHz
1066 MHz 800 MHz
Dual rank
00D5028 (4 GB)
00D5040 (8 GB)
00D5048 (16 GB)
1866 MHz
1.35 V 1.5 V
1.5 V 1.5 V
24 24
16 GB 16 GB
384 GB 384 GB
256 GB 128 GB
1600 MHz 1866 MHz
1600 MHz 1600 MHz
1066 MHz 1066 MHz
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