Green IT Amsterdam Region and the Software Improvement Group (SIG) organized the first workshop of the Green Software Community, with as theme 'Green Software Architecture'. For more information, please visit www.greenitamsterdam.nl/greensoftwarecommunity/ This is a presentation by Kay Grosskop of SIG on energy efficiency versus performance optimiziation

1. It’s most interesting when nothing happens
Workshop on green software architecture - Kay Grosskop
7 june 2011 T +31 20 314 0950
info@sig.eu
www.sig.eu

2. Energy proportionality
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Hoelzle/Barroso (google): Energy Proportionality as important system property
Typically the worst efficiency on low utilization.!
Most of the time systems are in low utilization.!
It’s most interesting when nothing happens

3. Focus on regions with low load
I 22
Difference between performance and energy optimizations:
• Performance: optimizations on high load regions.
• Energy Efficiency: optimizations in low load regions.
The ‘energy bottlenecks’ are where there is low load, but no energy proportionality
of the consumed resources is given.
• Optimizations should improve utilization (storage, cpu)
Otherwise: get idle and stay idle
• Enable the underlying layers (middleware, os, virtualization, hardware) to use energy
saving modes.
• Reduce the footprint of your application at low load or idle.
• Reduce polls, use events
• Release unused resources as soon as possible
It’s most interesting when nothing happens