What is SSD (Solid State Drive)

[EricTheRed]

Today, it is not only hard drive that is the big word when it comes to storage. SSD is an abbreviation you can learn first as last and that means many new benefits for your PC.

But first things first: SSD stands for Solid State Drive. The main physical difference between an SSD device and a standard hard drive is a hard disk consists of discs and read-write heads, plus a motor that spins the disc (or discs, if there are any).

A SSD device on its side, contains no moving parts. Instead contains an SSD device a special type of memory chips with rewritable cells that can retain data even when they are denied. Purely practical, you can often compare a SSD device with an overgrown memory stick.

Solid State Drive

What is a Solid State Drive ?

The original usage of the term solid-state refers to the use of semiconductor devices rather than electron tubes, but in this context, has been adopted to distinguish solid-state electronics from electromechanical devices as well. With no moving parts, solid-state drives are less fragile than hard disks and are also silent; as there are no mechanical delays, they usually employ low access time and latency.

Solid state is an electrical term that refers to electronic circuitry that is built entirely out of semiconductors. The term was originally used to define those electronics such as a transistor radio that used semiconductors rather than vacuum tubes in its construction. Most all electronics that we have today are built around semiconductors and chips. In terms 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.

[EricTheRed]

SSD devices have many advantages:

• A SSD device creates no noise
• A device with no moving parts is not nearly as fast in pieces because of shock or fall.
• SSD is generally a lower power consumption than conventional hard drives, so they often cooler.
• When the device does not generate much heat, do not need the fan in your computer go as much. You get a PC that Positioners in addition do not use up battery time like soon.
• Search time for an SSD device is much lower than on a hard drive.
• Larger range of operating temperatures. Typical hard drives have an operating range of 5-55 degrees C. Most flash drives can operate at 70 degrees, and some industrial grade drives can operate over an even wider temperature range.
• For low-capacity SSDs, lower weight and size: although size and weight per unit storage are still better for traditional hard drives, and microdrives allow up to 20 GB storage in a CompactFlash 42.8×36.4×5 mm (1.7×1.4×.2 in) form-factor. Up to 256 GB, as of 2008 SSDs are lighter than hard drives of the same capacity.

However, there are also some disadvantages:

• A SSD unit has an expected number of read and write cycles. When the number of cycles at the limit, the device will function worse.
• The price per GB of storage capacity is significantly higher for SSD than the HDD.
• Slower write speeds: As erase blocks on flash-based SSDs generally are quite large (e.g. 0.5 - 1 megabyte), they are far slower than conventional disks during small writes (the smaller, the worse) and can suffer from write fragmentation, and in some cases for sequential writes. SSDs based on DRAM, which do this several orders of magnitude faster than conventional disks, do not suffer from this problem.

SSD devices can use several different types of memory, respectively SLC (Single level cell) and MLC (Multi level cell). SCL has one bit of data per cell, while MLC technology involves multiple bit data per cell. MLC devices are cheaper to produce, but generally provide lower performance and higher energy consumption than SLC units.

The practical difference between the two memory types are durable, in practice, how many times each cell can input over before it starts to lose data.

Today, the MLC memory that are commonly use.

In addition to devices that are used internally in computers, the SSD devices in external format, in the same way as external hard drives. These connects easily to your PC with a cable.

[EricTheRed]

What is important?

When buying a SSD device, it is certain things that determine what device you should go for. The most important thing you should look for:

• I/O operations per second. The rule is simple: The more the better. It is not all the manufacturers that provide this. Those who do like to enter writing and reading each, with file sizes of the 4 Kbit and 100 percent random. The number of I/O operations per second has a lot to say for the performance. Intel's x25-E has stated such 35000 I/O operations per second for reading and 3300 writing, which is very good.
• Another important point is to read and write speed. This is defined by the number of megabytes per second. In general we can say that the good read performance in writing is from 150 MB per second and upwards, while a good write performance is from 80 MB per second and upwards. The hottest models on the market now is around 250 MB/s reading and just over 200 MB/s writing.

[EricTheRed]

SSD-challenges

SSD devices have a number of challenges to overcome before they probably will have as great a share of the market as regular hard drives.

One of the challenges is the storage capacity. Today you can find like SSD devices up to 250 GB commercially available devices up to 1 TB are released. Regular hard drives get up to 1.5 TB.

Development goes forward, however, in a fantastic pace, and we expect that the low storage capacity will not be any issue about a few years.

SSDs and Microsoft Windows: Windows is optimized for hard disk drives rather than SSDs. Microsoft created ReadyBoost to exploit characteristics of USB-connected flash devices, but Windows operating systems are not optimized for use of SSDs. Microsoft's latest OS Windows 7 which is still in beta, is optimized for SSDs as well as hard disks.

The other big challenge is cost. For a 250 GB SSD device, you can expect to pay over 6500 dollars. A standard hard drive with 500 GB of storage, you do not pay more than around 500 dollars for. Currently, it's already talk about the very high cost per GB if you choose to buy rather SSD hard drive.

[EricTheRed]

The market today

Several major manufacturers produce SSD devices. Intel, for example, launched 80 GB unit x25-M. Samsung is also on the hawks in SSD-race, and stepped up last year by launching a 128 GBs unit.

OCZ, Gskill, Sandisk, and Mtron is among the other manufacturers that have launched SSD devices.

Such development is today, it seems that the manufacturers will get a proper speed for the production of SSD units during the year to come.