IBM NeXtScale System, Planning And Implementation Manual

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Chapter 4. IBM NeXtScale nx360 M4 compute node
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4.6 Memory options
IBM DDR3 memory is compatibility tested and tuned for optimal IBM System x
performance and throughput. IBM memory specifications are integrated into the
light path diagnostic tests for immediate system performance feedback and
optimum system uptime. From a service and support standpoint, IBM memory
automatically assumes the IBM system warranty, and IBM provides service and
support worldwide.
The NeXtScale nx360 M4 supports DDR3 memory. The server supports up to
four DIMMs when one processor is installed and up to eight DIMMs when two
processors are installed. Each processor has four memory channels. There is
one DIMM per memory channel (1 DPC).
Figure 4-6 shows the memory channel layout.
Figure 4-6 Memory channel layout of the IBM NeXtScale nx360 M4
b. Processor detail: Model, cores, core speed, L3 cache, memory speed, and TDP power.
Floating point performance: The number of sockets and the processor
option that are selected determine the theoretical floating point peak
performance, as shown in the following example:
#sockets x #cores per processor x freq x 8 flops per cycle = Gflops
A nx360 compute node with dual socket E5-2680 v2 series 10-core that
operates at 2.8 Ghz has the following peak performance:
2 x 10 x 2.8 x 8 = 448 Gflops
DIMM 3 DIMM 2 DIMM 1
Xeon E5-2600 v2
Processor 1
Channel A
Memory Controller
Channel B Channel C
QPI links
DIMM 4
Channel D
DIMM 7 DIMM 6 DIMM 5
Xeon E5-2600 v2
Processor 2
Channel A
Memory Controller
Channel B Channel C
DIMM 8
Channel D