IBM eX5 Implementation Guide

Chapter 3. IBM System x3850 X5 and x3950 X5 79

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).

Table 3-12 DIMMs supported in the MAX5

3.8.2 DIMM population sequence

This section describes the order in which to install the memory DIMMs in the x3850 X5 and

MAX5.

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.

Part

number

MAX5

feature

code

Memory Supporte

d

in MAX5

Memory

speed

a

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.

Ranks

44T1592 2429 2 GB (1x 2GB) 1Rx8, 2Gbit PC3-10600R DDR3-1333

Yes 1333 MHz

b

b. Although 1333 MHz memory DIMMs are supported in the x3690 X5, the memory DIMMs run at a maximum speed

of 1066 MHz.

Single x8

44T1599 2431 4 GB (1x 4GB), 2Rx8, 2Gbit PC3-10600R DDR3-1333

Yes 1333 MHz Dual x8

46C7482 2432 8 GB (1x 8GB), 4Rx8, 2Gbit PC3-8500 DDR3-1066

Yes 1066 MHz Quad x8

46C7483 2433 16 GB (1x 16GB), 4Rx4, 2Gbit PC3-8500 DDR3-1066

Ye s

c

d

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.

1066 MHz Quad x4

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.