Today, SanDisk unveiled an advanced flash file system for solid-state drives (SSDs) that yields dramatic improvement in performance and reliability for computing applications. This next generation of patented flash management is called ExtremeFFS, and has the potential to accelerate random write speeds by up to 100 times over existing systems.
It has been discussed by reliable sources that the reason it takes so long to copy media to the iPhone is flash's slow write speeds. This is theorized because the relatively slow write speed of flash can have a bottleneck effect at certain times during certain applications and uses, although most of the time write operations are "fire and forget."
Recently, flash has made improvements in write speeds, but NAND flash will always be somewhat challenged in this aspect, because the way that writes work with the technology. In order to write data to a nonempty flash sector, you have to first erase that sector and then write to the newly emptied area. This erase-before-write need basically means writes are slow because they often take two operations to complete.
This challenge is worse for random writes than it is for streaming writes, because a single erasure of one substantial section of storage can accommodate a batch of multiple writes. In contrast, each individual of random writes must first be preceded by an individual erase. Most operating system’s drivers expect for a mass storage device to be structured like a hard disk, however flash is structured in the usual RAM grid structure and this means that there must be a way for mapping the OS model of filesystem locations onto the physical flash hardware.
In more detail, the ExtremeFFS works as such;
“In the case of ExtremeFFS, this OS-to-physical mapping is not static. Rather, the controller and software work with the flash to do dynamic mapping, so that related file blocks are clustered together for maximum streaming read performance, and random erase/write operations are distributed based on a number of reliability and performance factors. In regard to the latter, random writes can be cached and then actually written to the disk at the optimal time and location in order to cut down on the number of erases per write.”
The ExtremeFFS will start shipping in 2009, so who knows maybe faster iPhones are waiting somewhere down the line.
Thanks to “Poseidon79,” for letting me know about this story!
Source: SanDisk claims hundredfold flash speed boost for writes