Chapter 4. IBM System x3690 X5 1274.5 MAX5As introduced in 4.1.2, “IBM MAX5 memory expansion unit” on page 121, the MAX5 memoryexpansion drawer is available for the x3690 X5. Certain standard models include the MAX5,as described in 4.3, “Models” on page 124, and the MAX5 can also be ordered separately, aslisted in Table 4-3.Table 4-3 Ordering information for the IBM MAX5 for System xThe eX5 chip set in the MAX5 is an IBM unique design that attaches to the QPI links as anode controller, giving it direct access to all CPU bus transactions. It increases the number ofDIMMs supported in a system by a total of 32, and also adds another 16 channels of memorybandwidth, boosting overall throughput. The MAX5 adds additional memory performance.The eX5 chip connects directly through QPI links to both CPUs in the x3690 X5, and itmaintains a directory of each CPU’s last-level cache. This directory allows the eX5 chip torespond to memory requests prior to the end of a broadcast snoop cycle, thereby improvingperformance. For more information about eX5 technology, see 2.1, “eX5 chip set” on page 16.Figure 4-10 shows a diagram of the MAX5.Figure 4-10 MAX5 block diagramPart number Feature code Description59Y6265 4199 IBM MAX5 for System x60Y0332 4782 IBM 675W HE Redundant Power Supply59Y6269 7481 IBM MAX5 to x3690 X5 Cable Kit (two cables)SMIlinksDDR3 DIMMs(Two DIMMs per channel) MemorybufferMemorybufferMemorybufferMemorybufferSMIlinksMemorybufferMemorybufferMemorybufferMemorybufferDDR3 DIMMs(Two DIMMs per channel)External connectorsQPI QPIQPI QPI EXA EXA EXAIBM EXAchipQPI QPI
