The Storage Networking Industry Association (SNIA) today announced the release of a specification that can be used to test the performance of solid-state drives, regardless of the vendor.
SNIA, an industry trade group of vendors and universities that develops and promotes standards for storage systems, said its Solid State Storage Initiative (SSSI) came up with the SSD Performance Test Specification to level the playing field in benchmark testing.
[ Keep up on the day's tech news headlines with InfoWorld's Today's Headlines: Wrap Up newsletter. ]
The SSSI is releasing two versions of the test specification: one this week for enterprise SSDs, and another for server or client-side SSDs, which will be released in the third quarter of this year.
The Enterprise Performance Test Specification (PDF document) defines a set of device level tests and methodologies intended to enable comparative testing of SSD devices in enterprise systems, such as storage arrays.
Previously, there has been no widely accepted test methodology for measuring SSD device performance. Each SSD manufacturer utilized different measurement methodologies to derive performance specs for their products.
"You couldn't compare one data sheet to another data sheet and expect to understand if one drive was faster than another because the manufactures used different metrics," said Paul Wassenberg, chairman of the SSSI Governing Board.
"Today, the SSD market is where the HDD market was in the 1970s. There are a lot of different suppliers offering products with a lot of different abilities and there's a lot of variability," Wassenberg said.
More than 40 companies spent two years developing the Performance Test Specification (PTS), Wassenberg said. Among those companies were all of the major SSD and storage system manufacturers, including Samsung, Intel, Marvell, Toshiba, IBM, Seagate, Dell, EMC, Hitachi Data Systems, and Western Digital.
Jim Handy, an analyst with the market research firm Objective Analysis who was on the specification's technical working group, said, "The SNIA test specification is not an end-all, but it is certainly a big step ahead of the specificatons that are commonly used by SSD makers."
Handy said one of the most important aspects of the specification is that it's careful to ensure that SSDs are first "pre-conditioned" prior to testing, meaning data is first written to them and then erased to break the drives in.
All SSDs slow down after initial use because once a sufficient amount of data has been written to them, the processor in the drive begins to move data around in a process known as the read-modify-erase-write cycle.
Simply put, when an SSD is new, data can be written to it without interference from management software. However, once the drive has had a certain amount of data written to it, the NAND flash memory used to make SSDs requires that old data first be marked for deletion before new data memory. Then, once the new data is written, the old blocks marked for deletion are actually deleted in a process known as "garbage collection."