A Successful Flash Memory Summit for SSSI

SSSI had a busy booth at FMS.  Show attendees stopped by to discuss the newly released Client Performance Test Specification, and to see a demonstration of the high performance SSD product from member Texas Memory Systems.

We were honored to win a best-of-show award from FMS.  The Enterprise PTS won the Best Enterprise Application category.  The judges were impressed by the industry-wide cooperative effort that went into creating the specification.

It was exciting to hear from companies who have implemented or are planning to implement the PTS.  Watch for some case studies to be posted to the SSSI site. 

A successful show in all respects.

Client Performance Test Specification Released

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.

PCs: Better Boost from Flash than DRAM!

Objective Analysis has just published a new study with a somewhat surprising finding – that PCs get a bigger performance improvement by adding a dollar’s worth of NAND flash than by adding a dollar’s worth of DRAM.

This finding is the result of a series of nearly 300 benchmarks in which the company tested PCs with a variety of DRAM and NAND flash sizes running industry-standard benchmarks: PCMark, SYSmark, HDxPRT, and others.

In a nutshell the benchmarks showed that dollar-for-dollar NAND yields a greater performance improvement to a PC than does DRAM.  Once PC users and OEMs discover this phenomenon there should be a mass-migration of PC architectures to systems with paired storage (there’s a SNIA Webcast on this), perhaps in hybrid HDDs, and this will present difficulties to DRAM makers whose biggest market is the PC.

Oddly enough, the study shows that the HDD is likely to remain in PCs for a while to come, since well-designed DRAM-Flash-HDD configurations perform nearly as fast as DRAM-SSD systems with prices and capacities that are similar to those of a conventional DRAM-HDD system.  Future PC users are likely to opt for adding NAND flash, rather than DRAM, to their systems when they upgrade.

The report is available for purchase at http://Objective-Analysis.com/Reports.html#DRAM-NAND.

Comments and questions are more than welcome.

Trim: The Basics

Apple recently announced Trim support for all SSD-capable Macs.  What is Trim?

The SSSI Glossary defines the Trim command as “A method by which the host operating system may inform a NAND Flash-based SSS device about which blocks of data are no longer in use and can be erased. Such blocks may then be written without having to erase them first, enhancing SSS device write performance.”

A drive’s internal Garbage Collection performs a similar task as Trim by erasing blocks that have been previously marked for deletion.  However, because of the way that many operating systems work, there will be some blocks that can be repurposed of which only the OS is aware; Trim addresses this issue.

For Trim to be functional, both the SSD and the OS must support it.  Most SSDs of recent vintage support Trim, but check the features list to be sure.

In addition to the Apple OS, anyone who’s been paying attention knows that Microsoft Windows 7 supports Trim.  And an increasing number of Linux versions support Trim, plus FreeBSD and OpenSolaris.  Wikipedia has a more detailed list.

New Resource about SSD Standards is Now Available

The SNIA SSSI site has a new page entitled Solid State Storage Standards Explained.   It provides an overview of standards on drivers, interfaces, connectors, form factors, security, and testing that must be considered when designing or evaluating an SSD.  There are links to each standards site to get further details. 

The page will be updated regularly and inputs are welcome.  Questions and comments may be sent to asksssi@snia.org.

Webcast – The Benefits of Solid State in Enterprise Storage Systems

Update:  A recording of this webcast is available here.

Presenter: Tom Coughlin, SNIA Solid State Storage Initiative and President, Coughlin Associates

Abstract: This session presents a brief overview of the solid state technologies which are being integrated into enterprise storage systems today, including technologies, benefits, and price/performance. It describes where they fit into today’s typical enterprise storage architectures today, with descriptions of specific use cases. Finally, the session speculates briefly on what the future will bring.