= Surface Distance Cache Tests =

== Overview and Benchmark Procedure ==

I have externalized the caching functionality in our various fault surface classes. There are a couple different implementation of the new SurfaceDistanceCache interface:

* Traditional, single location cache: org.opensha.sha.faultSurface.cache.SingleLocDistanceCache
* Google guava loading cache with variable size: org.opensha.sha.faultSurface.cache.MultiDistanceCache
* Hybrid of both caches: org.opensha.sha.faultSurface.cache.HybridDistanceCache

I then ran lots of tests at HPCC with many variations on these caching schemes. All tests were run on nodes with the exact same configuration:

2 quad core 2.5 GHz processors, 12 GB RAM.

I ran the following benchmarks for a UCERF3 ERF with the branch average solution:

Distance test: how long does it take to calculate each distance metric from 80 sites to every rupture in the ERF?
Hazard test: how long does it take to calculate a hazard curve at 80 sites?

Sites are randomly distributed (tightly) around 35, -118. Tests were run with 1, 2, 4, and 8 threads (multiple runs of each configuration and times averaged).

== First Results and Sensitivity to Java Version ==