updated 09:25 am EST, Wed November 5, 2008
SanDisk on Wednesday said it has developed a way to eliminate one of the few performance bottlenecks of solid-state drives. A new flash file system known as ExtremeFFS uses a page-based method that no longer ties the logical location of data on the drive to its physical space. Instead, it dynamically writes and alters the position of data based on where it would be most efficient as well as the user's own habits.
The move should dramatically improve both performance and reliability, SanDisk says. Random write speeds, which are normally slow on SSDs, should be about 100 times faster than on current drives. Reliability will go up by reducing the tendency to write in the same physical space on a regular basis and thus to wear out some flash cells while others go untouched.
No products carrying ExtremeFFS have been announced, though SanDisk expects the first of these to ship sometime in 2009.
In addition to the new file system, SanDisk is also trying to foster the growth of the SSD business as a whole by promoting two abstract standards. Virtual RPM, or vRPM, would rate the performance of an SSD relative to the spin speed that would be necessary to match its testing. While not giving examples, the company expects 2009 drives to be as much as six times faster than a standard, notebook-sized 2.5-inch drive.
The second standard, Long-Term Data Endurance (LDE), would measure the amount of writes available to an SSD and would be used as a measure of the real lifetime of a drive versus older concepts such as Mean Time Between Failure. SanDisk believes the format would be a more accurate reflection of whether a particular drive is useful for longevity and has proposed the benchmark to the JEDEC standards group, which if it adopts LDE could see all SSD makers encouraged to rate their drives the same way.