Use of Solid state physics in storage

SSDs have been used in enterprise storage to speed up applications and performance without the cost of adding additional servers and with its solid state memory to store data technology it replaces the traditional hard disk drive.
The name solid state drive is nowhere related to its state of being liquid or solid; actually the term "solid-state" (from solid-state physics) refers to the use of semiconductor devices rather than electron tubes. But in the present context, it’s been used to distinguish solid-state electronics from electromechanical devices. Solid state drives also enjoy greater stability over their disk counterparts because it has no moving parts. With that solid-state drives are less fragile than hard disks and are also silent (unless a cooling fan is used); as there are no mechanical delays, they usually enjoy low access time and latency. For the first time Solid-state drive (SSD) technology has been marketed to the military and niche industrial markets in the mid-1990s.
Most all electronics that we have today are made up of semiconductors and chips. In case of a SSD, it refers to the fact that the primary storage medium is through semiconductors rather than a magnetic media such as a hard drive.
The look of SSD is no different than a traditional hard drive. This design enables the SSD drive to put in a notebook or desktop computer in place of a hard drive. To do this, it needs to have the standard dimension as a 1.8, 2.5 or 3.5-inch hard drive. It also will use either the ATA or SATA drive interfaces so that there is a compatible interface.
Actually this type of storage already exists in the form of flash memory drives that plug into the USB port. And for matter of fact solid state drives and USB flash drives both use the same type of non-volatile memory chips that retain their information even when they have no power. The difference comes in the form factor and capacity of the drives. While a flash drive is designed to be external to the computer system, an SSD is designed to reside inside the computer in place of a more traditional hard drive.
An SSD is commonly composed of DRAM volatile memory or primarily NAND flash non-volatile memory. Most SSD manufacturers use non-volatile flash memory to create more rugged and compact devices for the consumer market. These flash memory-based SSDs, also known as flash drives and don’t require batteries. They are often packaged in standard disk drive form factors (1.8-, 2.5-, and 3.5-inch). One more advantage of it is, non-volatility allows flash SSDs to retain memory even during sudden power outages, ensuring data persistence. But compare to DRAM SSDs, Flash memory SSDs are slower and some designs are even slower than traditional HDDs on large files, but flash SSDs have no moving parts and thus seek times and other delays inherent in conventional electro-mechanical disks are negligible.
SSDs based on volatile memory such as DRAM have ultrafast data access, generally less than 10 microseconds, and are used primarily to accelerate applications that would otherwise be held back by the latency of Flash SSDs or traditional HDDs. DRAM-based SSDs usually incorporate either an internal battery or an external AC/DC adapter and backup storage systems to ensure data persistence while no power is being supplied to the drive from external sources. If power is lost, the battery provides power while all information is copied from random access memory (RAM) to back-up storage. When the power is restored, the information is copied back to the RAM from the back-up storage, and the SSD resumes normal operation. (Similar to the hibernate function used in modern operating systems.) These types of SSD are usually fitted with the same type of DRAM modules used in regular PCs and servers, allowing them to be swapped out and replaced with larger modules.
Flash-based Solid-state drives are very functional and can be used to create network appliances from general-purpose PC hardware. A write protected flash drive containing the operating system and application software can substitute for larger, less reliable disk drives or CD-ROMs. Appliances built this way can provide an inexpensive alternative to expensive router and firewall hardware. NAND Flash based SSDs offer a potential power saving; however, the typical pattern of usage of normal operations result in cache misses in the NAND Flash as well leading to continued spin of the drive platter or much longer latency if the drive needed to spin up. These devices would be slightly more energy efficient but could not prove to be any better in performance.
On the other hand, Flash-memory drives have limited lifetimes and will often wear out after 1,000,000 to 2,000,000 write cycles (1,000 to 10,000 per cell) for MLC, and up to 5,000,000 write cycles (100,000 per cell) for SLC. Special file systems or firmware designs can mitigate this problem by spreading writes over the entire device, called wear leveling. Other issue of concern is security implications. For example, encryption of existing unencrypted data on flash-based SSDs cannot be performed securely due to the fact that wear leveling causes new encrypted drive sectors to be written to a physical location different from their original location—data remains unencrypted in the original physical location. Apart from these disadvantages capacity of SSDs is currently lower than that of hard drives. However, flash SSD capacity is predicted to increase rapidly, with drives of 1 TB already released for enterprise and industrial applications. The asymmetric read vs. write performance can cause problems with certain functions where the read and write operations are expected to be completed in a similar timeframe. SSDs currently have a much slower write performance compared to their read performance.
As a result of wear leveling and write combining, the performance of SSDs degrades with use. DRAM-based SSDs (but not flash-based SSDs) require more power than hard disks, when operating; they still use power when the computer is turned off, while hard disks do not.
To overshadow these disadvantages, Solid state drives have several advantages over the magnetic hard drives. The majority of this comes from the fact that the drive does not have any moving parts. While a traditional drive has drive motors to spin up the magnetic platters and the drive heads, all the storage on a solid state drive is handled by flash memory chips. This provides distinct advantages like Less Power Usage, Faster Data Access, and Higher Reliability. Solid state drives consume very less power in portable computers. Because there is no power draw for the motors, the drive uses far less energy than the regular hard drive. Another thing is SSD has faster data access, since the drive doesn't have to spin up the drive platter or move drive heads, the data can be read from the drive near instantly. Reliability is also a key factor for portable drives. Hard drive platters are very fragile and sensitive materials. Even small jarring movements from an impact can cause the drive to be completely unreadable. Since the SSD stores all its data in memory chips, there are fewer moving parts to be damaged in any sort of impact.
As with most computer technologies, the primary limiting factor of using the solid state drives in notebook and desktop computers is cost. These drives have actually been available for some time now, but the cost of the drives is roughly the same as the entire notebook they could be installed into.
The other problem affecting the adoption of the solid state drives is capacity. Current hard drive technology can allow for over 200GB of data in a small 2.5-inch notebook hard drive. Most SSD drives announced at the 2007 CES show are of the 64GB capacity. This means that not only are the drives much more expensive than a traditional hard drive, they only hold a fraction of the data.
All of this is set to change soon though. Several companies that specialize in flash memory have announced upcoming products that look to push the capacities of the solid state drives to be closer to that of a normal hard drive but at even lower prices than the current SSDs. This will have a huge impact for notebook data storage. SSD is a rapidly developing technology and Performance of flash SSDs are difficult to benchmark. And surely in the coming years it is going to extend its reach.