Category: Testing & Performance

Understand SSD Performance Project

Team_SSSI Leave a comment

At last week’s Storage Vision conference, SSSI announced the Understanding SSD Performance project, which is intended to educate users about how to use the SSS PTS (Performance Test Specification) to make intelligent decisions about SSD performance.  You can find the press release here.

The project outcomes so far include a new webpage at www.snia.org/forums/sssi/pts, a white paper (www.snia.org/forums/sssi/knowledge/education), and a webcast.

Join us for the webcast on January 19 at 11AM Pacific Time by going to www.brighttalk.com/webcast/663/40549.

 

Quick PTS Implementation

Jim Handy 2 Comments

PTS ProcedureNeed an abbreviated version of the SNIA SSD Performance Test Specification (PTS) in a hurry?  Jamon Bowen of Texas Memory Systems (TMS) whipped up a simple implementation of certain key parts of the PTS that can be run on a Linux system and interpreted in Excel.

It’s a free download on his Storage Tuning blog.

This is a boon for anyone that might want to run a internal preliminary test before pursuing a more formal route.

The bash script uses the Flexible I/O utility (FIO) to run through part of the SSSI PTS.  FIO does the heavy lifting, and the script manages it.  The script outputs comma separated (CSV) data and the download includes an Excel pivot table that helps format the results and select the measurement window.

Since this is a bare-bones implementation the SSD must be initialized manually before the test script is run.

The test runs the IOPS Test from the PTS.  This test covers a range of block sizes, read/write ratios and iterates until the steady state for the device is reached (with a maximum of 25 iterations).  Altogether the test takes over a day to run.

Once the test is complete, the downloadable pivot tables allow users to select the steady-state measurement window and report the data in a recommended format.

See Mr. Bowen’s blog at http://storagetuning.wordpress.com/2011/11/07/sssi-performance-test-specification/ for details on this valuable download.

Client Performance Test Specification Released

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Today, SSSI released the Client PTS.  Client refers to a single user / few tasks environment, as opposed to Enterprise, which implies multiple users / many tasks.  What are the differences between the Client and Enterprise PTS?

The Enterprise PTS calls out a Write Saturation test, where the SSD is written to continuously over the entire drive capacity 4 times or for 24 hours, whichever comes first.  This test provides a good idea of the robustness of the drive in an enterprise environment. This test is not applicable to Client environments, and was not included in the Client PTS.

The other three main types of tests measure IOPS, throughput (MB/sec), and Latency (how quickly a drive responds to commands) and are included in both Enterprise and Client PTS.  Here the Client PTS differs in that that tests may be performed on smaller segments of the drive, not all of the portions of the drive being tested need to be preconditioned, and different types of test stimulus are applied. These changes were based on the testing of literally dozens of different SSDs, as well as data provided by manufacturers of client SSDs.

The Client and Enterprise PTS documents can be downloaded at www.snia.org/pts.

Enterprise SSS Test Specification Released

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This week, the SSSI formally released the Enterprise Solid State Storage Performance Test Specification.   The SSS PTS provides standard test methodology for measuring the performance of Enterprise-class SSDs, so that the performance of products from different manufacturers may be fairly compared.  The press release can be found here. 

The Enterprise SSS PTS may be downloaded from here.

A Client (single user) SSS PTS is planned to be released in Q3 2011.

Enterprise Solid State Storage Performance Test Specification v1.0 Draft is Available

Team_SSSI 2 Comments

The Enterprise Solid State Storage Performance Test Specification v1.0 draft has been posted at http://www.snia.org/publicreview/ and is available for download.  [Update: released specification is now available here.]

The Enterprise SSS PTS provides a standard way of measuring the performance of SSDs for Enterprise applications, thus enabling fair comparisons of SSDs from different suppliers.

It is anticipated that final release of the Enterprise SSS PTS will occur in April 2011.

Work is ongoing in the  SSS Technical Work Group on development of a Client SSS PTS.

More information about the SSS PTS can be found at http://www.snia.org/forums/sssi/knowledge/education/.

SSD Blind Survey at Flash Memory Summit

Eden Kim Leave a comment

Calypso recently presented an Industry Blind Survey of SSD Performance at the Flash Memory Summit.

The survey compared (9) MLC, (8) SLC, and (1) 15K RPM SAS HDD.  The Chart shows all sample drives at RND 4K IOPS x Block Size for 65:35 R/W mix.  Small Blocks are in the back, large Blocks are in the front, IOPS are the Y axis.  This Chart clearly shows the general Steady State performance of SLC and MLC SSDs while referencing a 15K RPM SAS HDD.

Take aways?  There is a lot of variance in performance between SSDs, but it is nice to see an apples to apples comparison on a Device Level.  RND 4K IOPS at a 65:35 R/W mix is a good corner case benchmark.  All  numbers are Steady State and comply with the recently released SNIA SSS Performance Test Specification.   All measurements were taken on the SNIA compliant Calypso Reference Test Platform.