IBM eX5 Implementation Guide

Chapter 4. IBM System x3690 X5 133

The memory uses DDR3 technology and operates at memory speeds of 800, 978, and

1066 MHz. The memory speed is dictated by the memory speed of the processor (see

Table 4-5 on page 130). For more information about how this is calculated, see 2.3.1,

“Memory speed” on page 22.

4.8.1 Memory DIMM options

Table 4-7 shows the available memory options that are supported in the x3690 X5 server.

Table 4-7 x3690 X5/MAX5 Supported DIMMs

4.8.2 x3690 X5 memory population order

Memory DIMM installation is key to maximizing system performance. In this section, we

specify how to install DIMMs.

Figure 4-14 on page 134 shows the slot numbering for DIMM installation.

Part

number

x3690 X5

feature

code

Memory Supported

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 1712 2 GB (1x 2GB) 1Rx8, 2Gbit PC3-10600R DDR3-1333

Yes (fc 2429) 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 1713 4 GB (1x 4GB), 2Rx8, 2Gbit PC3-10600R DDR3-1333

Yes (fc 2431) 1333 MHz Dual x8

46C7448 1701 4 GB (1x 4GB), 4Rx8, 1Gbit PC3-8500 DDR3-1066 No 1066 MHz Quad x8

46C7482 1706 8 GB (1x 8GB), 4Rx8, 2Gbit PC3-8500 DDR3-1066

Yes (fc 2432) 1066 MHz Quad x8

46C7483 1707 16 GB (1x 16GB), 4Rx4, 2Gbit PC3-8500 DDR3-1066

Ye s

c

(fc 2433)

c. The 16 GB memory option is only supported in the MAX5 when it is the only type of memory used in the MAX5. You

cannot use any other memory options in the MAX5 if this option is installed in the MAX5. This DIMM also supports

redundant bit steering (RBS) when used in the MAX5, as described in “Redundant bit steering” on page 29.

1066 MHz Quad x4

Details:

򐂰 Only certain memory options supported in the x3690 X5 are also supported in the

MAX5, as indicated in Table 4-7. When ordering DIMMs for the MAX5 with feature

codes (configure-to-order (CTO) clients only), use the special MAX5 feature codes 24xx

as listed. See “MAX5 memory options” on page 137 for more information.

򐂰 Memory options must be installed in matched pairs. Single options cannot be installed;

therefore, the options listed must be ordered in a quantity of two.

򐂰 The maximum memory speed that is supported by Xeon 7500 and 6500 (Nehalem-EX)

processors is 1066 MHz. DIMMs will not run at 1333 MHz.

򐂰 Mixing DIMMs is supported by all DIMMs, except 16 GB DIMMs, and operates at the

speed of the slowest installed DIMM. We do not recommend mixing DIMMs for

performance reasons.

134 IBM eX5 Implementation Guide

Figure 4-14 x3690 X5 planar showing memory DIMM locations

One or two processors without the memory mezzanine

In this configuration, all of the system’s memory directly attaches to processor 1. If a second

processor is installed, it accesses main memory through processor 1, resulting in a

performance degradation to processor 2.

When the memory mezzanine is not installed, install the DIMMs in the order that is listed in

Table 4-8 on page 135. Only certain DIMM combinations result in Hemisphere Mode being

enabled. Hemisphere Mode improves memory performance, as described in 2.3.5,

“Hemisphere Mode” on page 26.

Tip: For performance reasons, install and populate the memory mezzanine if you install

the second processor.