Can't I just add Flash drives to my existing storage array?

Most disk arrays have not certified Flash drives for their enclosures, so for most people the answer is no.  As manufactures begin to certify Flash drives, they will need to re-architect their systems to leverage the performance of Flash storage.  The current architecture is not well designed for high bandwidth or high IOPS from individual disks, and a significant latency penalty (~1 ms) is imposed by the front-end to cache.  This latency is significant because the controllers were designed with disks in mind.  With disks as the backend storage, imposing a 1 ms overhead on a 5-20 ms disk response time was trivial; however, this overhead dwarfs Flash response time.  Additionally, buyers should be aware that there is a wide range between the performance and reliability of different Flash hard disk drives.  Our Flash-based RamSan products are architected from the ground up with Flash in mind and have dramatically lower latency than other systems.