Chapter 4. IBM System x3690 X5 135Table 4-8 One or two processor DIMM installation when the memory mezzanine is not installedTwo processors with memory mezzanine installedWith two processors installed in the system, memory is evenly distributed between bothprocessors, which maximizes system performance.Install the memory in the order that is listed in Table 4-9 on page 136. You are required toinstall a minimum of four DIMMs.Figure 4-15 on page 136 shows the DIMM numbering on the memory mezzanine.Number ofprocessorsNumber ofDIMMsHemisphere Mode aa. For more information about Hemisphere Mode and its importance, see 2.3.5, “Hemisphere Mode” onpage 26.Memory buffer Memory buffer Memory buffer Memory bufferDIMM 1DIMM 2DIMM 3DIMM 4DIMM 5DIMM 6DIMM 7DIMM 8DIMM 9DIMM 10DIMM 11DIMM 12DIMM 13DIMM 14DIMM 15DIMM 161 or 2 2 N x x1 or 2 4 Y x x x x1 or 2 6 N x x x x x x1 or 2 8 Y x x x x x x x x1 or 2 10 N x x x x x x x x x x1 or 2 12 Y x x x x x x x x x x x x1 or 2 14 N x x x x x x x x x x x x x x1 or 2 16 Y x x x x x x x x x x x x x x x xImportant: If using two processors with no mezzanine board, memory is not in anonuniform memory access (NUMA)-compliant state, which causes great performancedegradation. See 2.3.4, “Nonuniform memory architecture (NUMA)” on page 26 for details.Important VMware ESX considerations: When installing and running VMware ESX onthis server, the operating system might fail to install or boot with the following errormessage when the server memory configuration is not NUMA-compliant:“NUMA node 1 has no memory”There are only three possible configurations to support VMware: One processor is installed and no mezzanine board is installed. Two processors are installed and matching memory is installed on both the systemboard and the mezzanine board. Two processors are installed, no internal memory is installed, and the memory installedin an attached MAX5 memory expansion is configured as non-pooled memory.
