There is a misconception among few storage managers that SSD based appliances and flash based appliances are one and same. But there’s a difference existing in between these two kinds of appliances and they are as follows
SSD based appliances can use either drive form factor SSD or flash modules. From the vendor’s point of view the drive form factor SSD has an advantage of speed to market. These SSDs can be installed into a standard storage expansion bay. Typically storage vendors that use this technology are more focused on the storage software they develop more so than flash hardware design.
Flash based appliances are storage appliances that are made from flash modules not flash drives. This is an important differentiating factor because while these systems may be more difficult to bring to market because of their customization, they can potentially bring unique capabilities and memory density to the data center.
The other thing which is a bit confusing is the difference between a SSD and a flash array.
An SSD array would simply mean a flash based storage system that uses drive form factor SSD in a standard, off the shelf, storage server type of configuration. Here the main focus will be on the software which is driving the storage system. A flash array implies a storage system that is custom designed to use flash memory modules. The focus of flash array is on the configuration of hardware.
SSD/flash array means that the appliance has Array like functions beyond the basics of LUN provisioning. For example most SSD/flash arrays include snapshotting, deduplication, thin provisioning and replication.
Thus, now comes the big question?
SSD appliance or flash appliance- which is better or the best?
Factually speaking, this is a very difficult question to answer as vendors and analysts use these terms interchangeably.
So, better ask the storage vendor which is offering such appliances and go for a solution that can solve your performance troubles to the core and can fit into your budget on a perfect note.