ISS Technology Update Volume 8, Number 6

20% 20.1% 108,342 153 710

10% 10.0% 54,143 134 403

Active idle 0 124 0

Overall operations per watt 1,394

Calculating and interpreting SPECpower_ssj2008 results

The SPECpower_ssj2008 benchmark generates a final metric that is the overall operations-per-watt. This number is calculated

by adding together the number of Java operations performed at each target load and dividing this number by the sum of the

power consumptions at each target load. Thus, the overall operations-per-watt is an equally weighted average of the

performance to power ratio taken across the entire operating range of the server.

Overall operations-per-watt is useful for a general comparison of performance and power between servers; however, it may be

too broad a metric when considering specific application scenarios or utilization levels. If it is known that a server will be used

in a heavily loaded environment, it is more important to compare the performance-to-power ratios of the server at higher

utilizations and not focus as much on the overall performance–per-watt value.

SPEC Power futures

The SPECpower_ssj2008 is a relatively new, but increasingly important benchmark, and it continues to evolve. Version 1.10 of

the benchmark, announced in April 2009, has added support for server blade configurations. SPEC has also published

SPECweb2009, which is a power-oriented version of the SPECweb benchmark. Further developments in this area will be

happening relatively quickly since power efficiency in the data center remains an important topic.

To contact an HP spec representative, click here: spec@hp.com

Additional resources

For additional information on the topics discussed in this article, visit the following websites:

Source Email / Hyperlink

SPEC.org

SPECpower_ssj2008 main page

http://www.spec.org/power_ssj2008/

HP ProLiant Servers

Benchmarks page

http://h18004.www1.hp.com/products/servers/benchmark

s/index.html