SSD and Flash memory modules are alternative technologies to the traditional spinning hard drive for storing data and, in some cases, to the more expensive memory chips that in servers and storage arrays often act as cache memory.
SSDs and Flash memory modules offer multiple-times the performance of traditional spinning hard drives. And, because they have no moving parts, they use considerably less power than the traditional drives. However, because they are built using Flash memory chips instead of spinning platters, they are much more expensive on a per-gigabyte basis than hard drives.
Whether such products start to put a noticeable dent in the market for traditional hard drives in the foreseeable future is an open question. What’s not in question is their expected growth. Research firm IDC expects the SSD market to grow at a compound annual growth rate of 54 percent between 2008 and 2013.
Where the technologies are used varies. Customers put SSDs in arrays in place of spinning disks to serve as primary storage, where their much higher performance compared to hard drives more than makes up for their price premium.
Research firm IDC expects the SSD market to grow at a compound annual growth rate of 54 In some cases, SSDs can actually lower the cost of storage. For many high-performance applications, customers may often “short-stroke” their hard drives, or configure their hard drives so that only a small portion of the capacity is used to cut down on the seek time for data and increase throughput.
This results in higher performance, but at the cost of much lost capacity.The use of SSDs in many cases may result in lower costs because of the increased utilisation of storage capacity.
Customers are also putting SSDs or Flash storage modules in front of arrays to serve as a storage cache. In this case, the SSDs or modules are not actually acting as a primary storage device, but instead temporarily hold data that receives a lot of read requests, or hits, to speed up application performance.
PCIe cards from vendors such as LSI are also starting to become available for placing in servers to offer high-speed local storage and application performance, and a consortium of major storage and server vendors are developing a standard specification for PCIe-based SSDs.
SSDs are also increasingly available for use in laptop PCs not only because of their performance, but also because they use considerably less power and can boot a system up more quickly than spinning hard drives. Apple’s MacBookAir, introduced in the fall of 2010, can only be purchased with an SSD, and not with a hard drive. Toshiba, the manufacturer of the MacBook Air SSD, is also making that drive available to other portable PC OEMs.
But not all SSDs are created equal.