ExtremeFSS is a flash memory management system developed by SanDisk and revealed at the Microsoft Windows Hardware Engineering Conference (WinHEC) in Las Vegas, November 2008. The company claims that ExtremeFSS will boost the performance of Solid State Drives (SSD) significantly. It has the potential to increase random write speeds by up to 100 times. The system will allow data to be written to the drive without erasing and rewriting nearby data. The ExtremeFSS system will also boost the longevity of SSDs.

Currently available SSD drives are marketed as having significant advantages over mechanical spinning hard drives; they produce less heat , use less power and would seemingly be less prone to failure. However, in reality they were found to under-perform compared to standard mechanical HDDs when they were first widely used in notebooks. When tested, the first generation of notebooks containing SSDs revealed that the SSD drives delivered about the same speed equivalent as a mechanical spinning drive at 1000RPM. Most notebook HDDs operate at 5400RPM.

They tend to be slower at writing small amounts of data to the memory, while performing quite well with large files. This isn't very convenient for excessive use. ExtremeFSS is SanDisks solution to these problems, and is expected to be put into use in SSD drives sometime in the near future.