IBM System x3850 X5 Implementation Manual page 155

Table 4-8 One or two processor DIMM installation when the memory mezzanine is not installed
Memory buffer
1 or 2 2 N x
1 or 2 4 Y x
1 or 2 6 N x
1 or 2 8 Y x
1 or 2 10 N x
1 or 2 12 Y x
1 or 2 14 N x
1 or 2 16 Y x
a. For more information about Hemisphere Mode and its importance, see 2.3.5, "Hemisphere Mode" on
page 26.
Important: If using two processors with no mezzanine board, memory is
nonuniform memory access (NUMA)-compliant state, which causes great performance
degradation. See 2.3.4, "Nonuniform memory architecture (NUMA)" on page 26 for details.
Important VMware ESX considerations: When installing and running VMware ESX on
this server, the operating system might fail to install or boot with the following error
message 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 system
board and the mezzanine board.
Two processors are installed, no internal memory is installed, and the memory installed
in an attached MAX5 memory expansion is configured as non-pooled memory.
Two processors with memory mezzanine installed
With two processors installed in the system, memory is evenly distributed between both
processors, which maximizes system performance.
Install the memory in the order that is listed in Table 4-9 on page 136. You are required to
install a minimum of four DIMMs.
Figure 4-15 on page 136 shows the DIMM numbering on the memory mezzanine.
Memory buffer
x x
x x
x x x
x x x
x x x x x
x x x x x
Memory buffer
x
x x
x x
x x x
x x x x
x x x x x
x x x x x
x x x x x
Chapter 4. IBM System x3690 X5
Memory buffer
x
x
x x
x x
x x x
x x x
x x x x x
not
in a
135