SSD or solid state disks are touted as the future of storage. They offer more stable storage than hard drives and faster seek times making the time taken to seek for informaiton much less. Hard drives have struggled to keep up with the pace of change that has been offered by computer processors and graphics chips. Hard drive capactiy gets larger and yet seek times do not always increase proportionally meaning that it is taking longer than it needs for us to get our informaiton. 

Hard drives are physically limted by having moving parts that move to where the information is stored on the disk. Although seek times can be quick there will always be a time where the mechanical components move. It takes more energy (and battery life in a laptop), and more noise and heat is generated as a result of there being moving parts. Furthermore, with moving parts, there is always the danger of mechanical failure - a part could fail and cause a head crash where the head of the drive hits the platter that stores informaiton and causes the information to be lost.

SSDs overcome these physcial limitations by using Flash memory (you may well have come across this in a memory stick, USB key or camera memory card). SSD memory has no moving parts, much quicker seek and read times and a much lower mean time between failure. Tests between hard drives and SSD drives repeatedly show how much quicker SSD drives are for all but reading and writing.

SSDs offer huge performance increases over standard drives with very few downsides. Drives use less electricity, are less prone to mechanical failure, generate less heat and work quicker than their counterparts. The problem is cost. You may have noticed a 160gb hard drive based iPod doesn’t cost much different to its 16gb flash-based sibling. Flash memory is currently very expensive to produce  $5 per gigabyte year compared to $1 per gigabyte for hard drives) and, although prices are falling, the difference is still projected to be 3 times in 2010.

The good news comes in the form of Hwang’s Law (a spin on Moore’s Law which predicted the doubling of transistors on a chip every 18 months). According to Chang Gyu Hwang, CEO of Samsung’s Semiconductor business, the density of  Flash memory has doubled every year since 1999 and will continue to do so.

Conventional hard drives still have a future and will continue to have cost and density advantages (it is predicted that a 3.5″ drive will be able to hold up to 50tb by 2013) but capacity without speed causes longer seek times and frustrated customers. 

In the 1970s SSDs were used in the memory of early supercomputers but their high price meant that they were not pursued. 

In 1978, StorageTek developed the first modern type of solid-state drive.

In the mid-1980s Santa Clara Systems introduced BatRam, an array of 1 megabit DIP RAM Chips and that emulated a hard disk. The Sharp PC-5000, introduced in 1983, used 128 kilobyte (128kb) solid-state storage cartridges.

RAM "disks" were popular as boot media in the 1980s when hard drives were expensive, floppy drives were slow, and a few systems, such as the Amiga series, the Apple IIgs, and later the Macintosh Portable, supported this. 

In 1995 M-Systems introduced flash-based solid-state drives. (SanDisk acquired M-Systems in November 2006). Since then, SSDs have been used successfully as hard disk drive replacements by the military and aerospace industries, as well as other mission-critical applications.  

In 2007, SSD's of a few gigabytes capacity gained mainstream popularity with macbooks and Alienware notebooks introducing the drives.

It was only in 2008 that Intel entered the SSD market, partly as a way of giving more to customers with complex server systems. In December 2008, Intel announced 160gb 2.5 inch SSD drives, which tests have shown to be the quickest on the market.

Toshiba have been in the SSD market for a few years, recently announcing a 512gb drive for notebooks.

Samsung are a big competitor in the SSD market after having made Flash memory for cameras etc for years.

SanDisk have been manufacturing Flash memory for over a decade and are a major player. SanDsik have posted a 21% revenue decline in the last quarter, however.

There are a number of SSD manufcturers, but these are the most well-known.