Dimm Population Sequence - IBM System x3850 X5 Implementation Manual

MAX5 memory
The MAX5 memory expansion unit has 32 DIMM sockets and is designed to augment the
installed memory in the attached x3850 X5 server. Table 3-12 shows the available memory
options that are supported in the MAX5 memory expansion unit. These options are a subset
of the options that are supported in the x3850 X5 because the MAX5 requires that all DIMMs
use identical DRAM technology: either 2 Gb x8 or 2 Gb x4 (but not both at the same time).
x3850 X5 memory options: The memory options listed here are also supported in the
x3850 X5, but under other feature codes for configure-to-order (CTO) clients. Additional
memory options are also supported in the x3850 X5 server but not in the MAX5; these
options are listed in Table 3-11 on page 78.
Table 3-12 DIMMs supported in the MAX5
Part MAX5 Memory
number feature
code
44T1592 2429 2 GB (1x 2GB) 1Rx8, 2Gbit PC3-10600R DDR3-1333
44T1599 2431 4 GB (1x 4GB), 2Rx8, 2Gbit PC3-10600R DDR3-1333
46C7482 2432 8 GB (1x 8GB), 4Rx8, 2Gbit PC3-8500 DDR3-1066
46C7483 2433 16 GB (1x 16GB), 4Rx4, 2Gbit PC3-8500 DDR3-1066
a. Memory speed is also controlled by the memory bus speed, as specified by the selected processor model. The
actual memory bus speed is the lower of both the processor memory bus speed and the DIMM memory bus speed.
b. Although 1333 MHz memory DIMMs are supported in the x3690 X5, the memory DIMMs run at a maximum speed
of 1066 MHz.
c. The 16 GB memory option is supported in the MAX5 only when it is the only type of memory used in the MAX5.
No other memory options can be used in the MAX5 if this option is installed in the MAX5.
d. This DIMM supports redundant bit steering (RBS), as described in "Redundant bit steering" on page 29.
Use of the 16 GB memory option: The 16 GB memory option, 46C7483, is supported in
the MAX5 only when it is the only type of memory that is used in the MAX5. No other
memory options can be used in the MAX5 if this option is installed in the MAX5.
Redundant bit steering: Redundant bit steering (RBS) is not supported on the x3850 X5
itself, because the integrated memory controller of the Intel Xeon 7500 processors does
not support the feature. See "Redundant bit steering" on page 29 for details.
The MAX5 memory expansion unit support RBS, but only with x4 memory and not x8
memory. As shown in Table 3-12, the 16 GB DIMM, part 46C7483, uses x4 DRAM
technology. RBS is automatically enabled in the MAX5 memory port, if all DIMMs installed
to that memory port are x4 DIMMs.

3.8.2 DIMM population sequence

This section describes the order in which to install the memory DIMMs in the x3850 X5 and
MAX5.
Supporte
d
in MAX5
Yes
Yes
Yes
c d
Yes
Chapter 3. IBM System x3850 X5 and x3950 X5
Memory Ranks
a
speed
b
1333 MHz Single x8
1333 MHz Dual x8
1066 MHz Quad x8
1066 MHz Quad x4
79