Created on: January 6, 2016
Unless you have disabled it, occasionally the Spolight indexing feature in OS X will run in the background when you are using other applications. Spotlight indexing can (for a brief time) cause other applications that are running — including benchmark software — to run less efficiently. If you run benchmarks on a drive and get unexpected results, please make sure Spotlight was not running during that process and run the benchmark again to make sure the results were not skewed.
Note that the same side effect can occur if OS X is set to perform regular Time Machine back-ups, and Time Machine begins to run in the background while you are using other apps. Both Spotlight and Time Machine require enough system resources that they will tend to impact the performance of those apps.
To learn more about available features and options with Spotlight and Time Machine please visit: http://support.apple.com/
Contributors: Anthony D.