Chapter 3. IBM System x3850 X5 and x3950 X5 79MAX5 memoryThe MAX5 memory expansion unit has 32 DIMM sockets and is designed to augment theinstalled memory in the attached x3850 X5 server. Table 3-12 shows the available memoryoptions that are supported in the MAX5 memory expansion unit. These options are a subsetof the options that are supported in the x3850 X5 because the MAX5 requires that all DIMMsuse 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 MAX53.8.2 DIMM population sequenceThis section describes the order in which to install the memory DIMMs in the x3850 X5 andMAX5.x3850 X5 memory options: The memory options listed here are also supported in thex3850 X5, but under other feature codes for configure-to-order (CTO) clients. Additionalmemory options are also supported in the x3850 X5 server but not in the MAX5; theseoptions are listed in Table 3-11 on page 78.PartnumberMAX5featurecodeMemory Supportedin MAX5Memoryspeed aa. Memory speed is also controlled by the memory bus speed, as specified by the selected processor model. Theactual memory bus speed is the lower of both the processor memory bus speed and the DIMM memory bus speed.Ranks44T1592 2429 2 GB (1x 2GB) 1Rx8, 2Gbit PC3-10600R DDR3-1333 Yes 1333 MHzbb. Although 1333 MHz memory DIMMs are supported in the x3690 X5, the memory DIMMs run at a maximum speedof 1066 MHz.Single x844T1599 2431 4 GB (1x 4GB), 2Rx8, 2Gbit PC3-10600R DDR3-1333 Yes 1333 MHz Dual x846C7482 2432 8 GB (1x 8GB), 4Rx8, 2Gbit PC3-8500 DDR3-1066 Yes 1066 MHz Quad x846C7483 2433 16 GB (1x 16GB), 4Rx4, 2Gbit PC3-8500 DDR3-1066 Yesc dc. 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 x4Use of the 16 GB memory option: The 16 GB memory option, 46C7483, is supported inthe MAX5 only when it is the only type of memory that is used in the MAX5. No othermemory 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 X5itself, because the integrated memory controller of the Intel Xeon 7500 processors doesnot 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 x8memory. As shown in Table 3-12, the 16 GB DIMM, part 46C7483, uses x4 DRAMtechnology. RBS is automatically enabled in the MAX5 memory port, if all DIMMs installedto that memory port are x4 DIMMs.
