Dell POWEREDGE M915 - Manual (Page 19)

Power Efficiency Comparison of the Dell PowerEdge M915 and HP ProLiant BL680c G7 Blade Solutions
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Appendix A—Test Methodology
SPECpower_ssj2008 Standard
SPECpower_ssj2008 is an industry standard benchmark created by the Standard Performance Evaluation
Corporation (SPEC) to measure a server’s power and performance across multiple utilization levels.
SPECpower_ssj2008 consists of a Server Side Java (SSJ) workload along with data collection and control
services. SPECpower_ssj2008 results portray the server’s performance in ssj_ops (server side Java operations
per second) divided by the power used in watts (ssj_ops/watt). SPEC created SPEcpower_ssj2008 for those
who want to accurately measure the power consumption of their server in relation to the performance that the
server is capable of achieving with ssj2008 workload.
SPECpower_ssj2008 consists of three main software components:
 Server Side Java (SSJ) Workload—Java database that stresses the processors, caches and memory of
the system, as well as software elements such as OS elements and the Java implementation chosen
to run the benchmark.
 Power and Temperature Daemon (PTDaemon)—Program that controls and reports the power
analyzer and temperature sensor data.
 Control and Collect System (CCS)—Java program that coordinates the collection of all the data.
For more information on how SPECpower_ssj008 works, see http://www.spec.org/power_ssj2008/.
All results discussed in this whitepaper are from “compliant runs” in SPEC terminology, which means that
although they have not been submitted to SPEC for review, Dell is allowed to disclose them for the purpose of
this study. All configuration details required to reproduce these results are listed in Appendices A, B, and C
and all result files from the runs compared are included in Appendix D.
Both servers were configured by installing a fresh copy of Microsoft
® Windows Server ® 2008 Enterprise R2
(Service Pack 1) with the operating system installed on a two-hard drive RAID 1, choosing the “full installation”
option for each.
The latest driver and firmware update packages available to both servers were installed at the beginning of
this study. Refer to Appendix B for details.
The Dell System Performance Analysis Team ran SPECpower_ssj2008 ten times per configuration across both
servers and chose the run with the highest overall ssj_ops/watt for each configuration to compare.
BIOS Settings
BIOS settings differed between the two manufacturers, so we tuned for best-known SPECpower_ssj2008
performance results. To improve power efficiency, we changed the memory speed of the M915 blades to
1066MHz from the default of 1333MHz, and changed their HyperTransport frequency to HT1. Virtualization was
not used in these tests, so AMD Virtualization support was disabled on both servers.
For the Dell PowerEdge M915 blades, the following settings were used:
 DRAM Prefetcher Disabled.
 Hardware Prefetch Training on Software Prefetch Disabled.
 Hardware Prefetcher Disabled.
 HT mode set to HT1.
 Memory Speed set to 1066MHz in BIOS.
 AMD Virtualization was disabled.