Dell PowerEdge R820 - Manual (Page 19)

Performance Analysis of HPC Applications on Several Dell PowerEdge 12 th Generation Servers
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NAMD performance Figure 11.
4.8. Power consumption and energy efficiency
This section discusses the power consumption and the energy efficiency of the three clusters described
in
Test bed and applications . Energy efficiency is used as the metric for power comparisons and is
computed as performance obtained for each watt of power consumed.
The Dell PowerEdge M1000e chassis supports multiple server blades and includes shared infrastructure
such as fans, power supplies, management modules and switches. The power consumption of the
chassis includes the power consumed by these shared resources. Power measurements for a smaller
number of servers that do not fully make use of the chassis would not be a fair measure of the actual
power consumed. Therefore, only a fully populated PowerEdge M1000e blade chassis with 16
PowerEdge M620 servers or 32 PowerEdge M420 servers is used for this portion of the study. For the
PowerEdge R820 cluster, the power consumed by four PowerEdge R820s (128 cores) and the InfiniBand
switch are taken into consideration. The power consumed by the Gigabit Ethernet management switch
is not taken into account.
Note that the energy efficiency data presented here is not an apples-to-apples comparison. First, each
type of cluster has a different total core count; for example, different number of servers in the
cluster. Additionally, the results compare rack servers to blade servers. These results are an attempt to
extract trends and report measured results. An ideal comparison would compare similar types of
servers and identical number of cores in each of the three clusters.
Figure 12 presents the energy efficiency of HPL. The metric used here is GFLOPS/Watt. The PowerEdge
R820 cluster with 128 cores has 4 percent better efficiency than the 256 core PowerEdge M620 cluster.
This can be attributed to the lower core count of the PowerEdge R820 cluster; lower total
performance, but lower power consumption as well. The 512 core PowerEdge M420 cluster is 15
percent more energy efficiency than the 256 core PowerEdge M620 cluster. This is due to two factors -
double the core count on the PowerEdge M420 cluster boosts the performance. Additionally, the lower
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Number of Cores
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