Test Terminology

AR amount/segments (ActiveRange Amount and Segments):  The sum of the capacity referenced by the LBA’s that are accessed for a given Test or Preconditioning Code equal to, or less than the capacity referenced by the ActiveRange LBAs

AR Segments (ActiveRange Segments): A collection of contiguous and equal sized LBA ranges within the ActiveRange where the Test Code and Preconditioning Codes are allowed to access. The starting LBA of each ActiveRange Segment is randomly distributed across the entire ActiveRange.  The set of ActiveRange segments spans the ActiveRange.  Note that ActiveRange segments shall not touch to form a single segment.

AR Segment Size (ActiveRange Segment Size): Divide the ActiveRange Amount by the number of ActiveRange Segments as prescribed in the Test Code or Preconditioning Code. The number of AR Segments is further defined  in the PTS for IOPS, TP and LAT tests as 2,048 segments.

Device I/F (Device Interface): The SSD interface, i.e., SATA 3Gb/s or SAS 6Gb/s.

Duration of Test (T or GB): An optional WSAT test time duration measured in Time or Total GiB Written (TGBW) (PTS Enterprise)

PC AR (Preconditioning ActiveRange):  ActiveRange is defined as the range of LBA’s that can be used for a given Test Code or Preconditioning Code expressed as a percent of the total addressable LBAs. Preconditioning ActiveRange is therefore the range of LBA's available to be used for Preconditioning. 

Preconditioning: The process of writing data to the device to prepare it for Steady State measurement; consists of two steps  1) Workload Independent Preconditioning (WIPC) and 2) Workload Dependent Preconditioning (WDPC). 

Purge: The process of returning a SSD to a state in which subsequent writes execute, as closely as possible, as if the device had never been used and does not contain any valid data.

QD / TC (Queue Depth and Thread Count): Outstanding IOs is the number of IO operations issued by a host, or hosts, awaiting completion. OIO/thread is the number of OIO allowed per Thread (Worker or Process).  Queue Depth (or QD) is the number of IOs per Thread while Thread Count (or TC) refers to the number of processes generated by the stimulus generator.

Round: A complete pass through all the prescribed test points for any given test

SS Rounds (Steady State Rounds): The number of Rounds required for the test tracking variable to meet the PTS Steady State Determination Criteria (applies to IOPS, TP, and LAT tests in PTS Client).

Test AR (Test ActiveRange): The range of LBA's available to be used for the Test Code.

Test System: The test platform used for the testing, in this case, a Calypso Reference Test Platform (RTP 2.0) using Calypso CTS 6.5 test software (www.calypsotesters.com).

Workload Independent Preconditioning (WIPC): The first Preconditioning step comprised of a prescribed workload, unrelated to the test workload, as a means to facilitate convergence to Steady State.  WIPC for IOPS, TP and LAT is writing 2X (twice) the user capacity in SEQ 128K Writes.  WIPC is used to expedite convergence to Steady State by quickly touching each LBA twice prior to writing the test code WDPC.

Workload Dependent Preconditioning (WDPC): The second Preconditioning step comprised of running the test workload itself, after Workload Independent Preconditioning, as a means to put the device in a Steady State relative to the dependent variable being tested. 

WSAT Steady State (Write Saturation Test Steady State): The area where the IOPS measurements are relatively time invariant, or the generally level area of the plot on after completion of the transition zone.
 

Further descriptions of the above terms and others can be found in the  SSS PTS or SSSI Glossary.