Thursday, November 26, 2015
SSD Review
Solid-State Drive (SSD) is a data storage medium using nonvolatile memory as a medium and not using magnetic discs like a conventional hard disk drive. In contrast to volatile memory (RAM programs), data stored on SSD will not be lost even if there is no electrical power.
History
History data storage without using any moving components is actually already begun since the late 1960 's and early 1970 's., SSD solely to artificial IBM super computer, Amdahl and Cray. However, the expensive price to pay, make SSD could not be produced because of the uneconomical masse (at that time only created if there are orders).
The project then begins again with SSD presence SSD made by StorageTek 5800 in the late 1970s. at the beginning of the 1980s, Santa Clara Systems introduced BatRam, an array of shape memory RAM chip with a total capacity of 1 megabit (125 kilo byte) which serves to emulate the hard-disk, a storage medium that is large enough, because MS-DOS version 1.0 only supports a maximum storage of 160 kilo byte only. In the package, this memory is equipped with rechargeable batteries. This function saves the battery when the data set of RAM doesn't get electrical power supply (e.g. when the computer is turned off).
In 1995, the M-Systems introduced flash-based SSD memory. SSD is then widely used by the military and space industry of United States in lieu of conventional hard-disk function. Since then, growing so are SSD in a device that we know today and start mass produced so much more affordable at this time (although the usual hard-disk is still much cheaper).
Features and Technology
From the side of his nature, SSD can be classified into two, namely flash-based and US-based DRAM (Dynamic Random Access Memory).
In the market today we meet many flash-based SSD technologies, such as Flash Disk, Secure Digital (SD Card), Micro SD Card, Multi Media Card (MMC), Compact Flash (CF). While the physical sizes of SSD with hard-disk, i.e. the size of conventional 1.8-inch and 2.5-inch with a capacity of up to 128 GB, above since 2008 have started gaining popularity in the market along with a more affordable price.
Flash-based SSD make use of a small amount of DRAM for cache is used to store information about the placement of a block of data as well as information on wear leveling (a technique to extend the age of flash-based memory usage). While on SSD with high performance usually also equipped with temporary electrical power storage (energy storage). These components are generally composed of a series of capacitors or batteries which served to move the data from the cache to the SSD flash memory when the computer is shut down/off suddenly (if the capacitor-based) or to store data temporarily in the cache (if using a battery).
Flash-Based SSD
The Data in the flash-based SSD usually stored in memory cells on a chip. In this group there are two types of memory cells are commonly used, namely type MLC (Multi Level Cell) and SLC (Single Level Cell).
Type MLC SSD is usually cheaper as compared to the SLC-based. This is due to the MLC store data of 3 or more bits per cell, whereas for SLC only 1 bit only, so the cost per giga byte him becomes lower.
Whereas the type SLC SSD worth more expensive, but it has its own type of advantages if compared with other types of MLC, the data transfer rate is higher, lower power consumption and durability of memory cells is longer. One cause of this is the expensive price of SLC fare making higher per giga-byte SSD SLC type his recall is only capable of storing data with fewer numbers per cell.
DRAM-Based SSD
SSD technology has data access speed is very high (generally less than 2 milli seconds). These devices are usually equipped with internal batteries and backup data storage systems to ensure the presence of data in the SSD anyway when the computer is turned off or sudden death. In this condition, the batteries in the SSD will supply power for a series of cells to copy all the information from the backup storage devices to DRAM. When the computer is powered on again, all of this information will be restored again to the DRAM.
SSD advantages Compared to conventional hard-disk
There are many advantages of Solid State drives compared to hard-disk, such as:
- Time to start working (start-up) faster. This resulted in higher data access, delay/delay (latency) reads the data at lower and data search time (seek time) which is much faster.
- Don't have a noisy/drone (noise) given the absence of a moving component.
- More efficient electrical power, although for DRAM-based SSD still required a fairly high power supplies, but when compared to a conventional hard-disk is far more energy efficient.
- More susceptible to shocks, vibrations, and high temperatures.
- With the same storage capacity, SSD has a lighter weight and sleeker physical size when compared to regular hard-disk (especially current up to 256 GB of storage size) so that the more portable for notebooks and mobile external storage.
- Because it can store data even if the power supply does not exist, then this SSD technology if combined with the Memristor technology (Memory Transistors) opens the possibility to achieve the creation of a computer like can turn on and turn off a TV, so the term start-up, shutdown, hang, blue screen and the like just being historical record for our grandchildren.
