Product guide

IBM System x3650 M4 13
Maximum number of ranks per one channel is eight (with the exception of 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:

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 "Max. operating
speed" section in Table 5.
The following table (Parts 1 and 2) shows the characteristics of the supported DIMMs. 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.
Table 5. Maximum memory speeds (Part 1: UDIMMs and RDIMMs)
DIMM
specification
UDIMM RDIMM
Rank Dual rank Single rank Dual rank Quad rank
Part numbers 49Y1404 (4 GB) 49Y1405 (2 GB)
49Y1406 (4 GB)
49Y1559
(4GB)
49Y1407 (4 GB)
49Y1397 (8 GB)
49Y1563 (16 GB)
90Y3178
(4GB)
90Y3109
(8GB)
00D4968
(16GB)
49Y1399 (8 GB)
Rated speed 1333 MHz 1333 MHz 1600 MHz 1333 MHz 1600 MHz 1066 MHz
Rated voltage 1.35 V 1.35 V 1.5 V 1.35 V 1.5 V 1.35 V
Operating voltage 1.35 V 1.5 V 1.35 V 1.5 V 1.5 V 1.35 V 1.5 V 1.5 V 1.35 V 1.5 V
Max. qty supported* 16 16 16 24 24 16 24 24 16 16
Max. DIMM capacity 4 GB 4 GB 4 GB 4 GB 4 GB 16 GB 16 GB 16 GB 8 GB 8 GB
Max. memory
capacity
64 GB 64 GB 64 GB 96 GB 96 GB 256 GB 384 GB 384 GB 128 GB 128 GB
Max. memory
at rated speed
32 GB 64 GB 64 GB 64 GB 64 GB 256 GB 256 GB 256 GB 128 GB 64 GB
Maximum operating speed
1 DIMM per channel 1333
MHz
1333
MHz
1333
MHz
1333
MHz
1600 MHz 1333
MHz
1333
MHz
1600 MHz 800
MHz
1066
MHz
2 DIMMs per
channel
1066
MHz
1333
MHz
1333
MHz
1333
MHz
1600 MHz 1333
MHz
1333
MHz
1600 MHz 800
MHz
800 MHz
3 DIMMs per
channel
NS** NS** NS** 1066
MHz
1066 MHz NS** 1066
MHz
1066 MHz NS** NS**
* Maximum quantity supported is shown for two processors installed. When one processor is installed, the
maximum quantity supported is a half of the quantity that is shown. Shaded cells indicate when all DIMM sockets
can be occupied.
** NS = Not Supported