+ write separation.
+
+latency_target=int If set, fio will attempt to find the max performance
+ point that the given workload will run at while maintaining a
+ latency below this target. The values is given in microseconds.
+ See latency_window and latency_percentile
+
+latency_window=int Used with latency_target to specify the sample window
+ that the job is run at varying queue depths to test the
+ performance. The value is given in microseconds.
+
+latency_percentile=float The percentage of IOs that must fall within the
+ criteria specified by latency_target and latency_window. If not
+ set, this defaults to 100.0, meaning that all IOs must be equal
+ or below to the value set by latency_target.