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Solid State Drives





Description:

Solid State Drives are a growing form of storage that replaces the traditional moving Hard Disk Drives. They use the same flash memory that USB thumb drives use. Solid State Drives come with many benefits such as faster read/write access and potentially less power consumption due to its lack of moving parts, which is a big plus for netbook and notebook users. The introduction of netbooks has opened the market for this type of technology being used instead of Hard Disk Drives, as netbooks typically do not come with as much storage and ideally have prolonged battery life. However, there are some downfalls to Solid State Drives such as the price, which is very high, just like every new and growing technology. A 160GB SSD, which is a larger capacity, goes for about $350 - $400 dollars while the traditional 500GB Sata HDD goes for about just under $100 dollars. That is a huge difference especially for those who tend to store a bunch of data such as music, and videos. SSD is not the way to go as of now for those who need to save money. Laptop users these days typically need more storage and are willing to compromise storage space for speed and battery life, but most are not willing to compromise that much of a difference in price just to get a faster speed and a longer battery life.

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SSD Architecture:
There are two types of Solid State Drives that exist on today’s market. The Multi-Level Cell (MLC) SSD's are slower and less reliable than the Single-Level Cell (SLC) SSD's that are almost double the cost. Although (MLC) is considered the lesser of the technologies, (MLC) SSD's far exceed traditional HDD's when it comes to speed, reliability and performance overall. Can you imagine paying $800 dollars for a 160GB of storage? Intel's X-25M shown in the picture above is an (MLC) SSD and personally owning one I can speak for its speed, battery improvement, and reliability. Booting my computer with a 5400rpm Sata HDD from start to finish took about 23 seconds total. After installing the X-25M this process was decreased to 9 seconds which is less than half of the time it previously took to do so. Applications run much faster as the SSD has a much faster read/write speed and battery life overall increased from about 3 to 3 1/2 hours. This increase may not seem like much but when you are on the run that extra half and hour comes in very handy. Intel also offers an X-25E SSD which uses the (SLC) technology and is supposedly much faster.
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Advantages:

  • There is no spin-up when the drive is booted, so it takes less time for SSDs to be usable
  • SSDs are less noisy because there are no moving parts
  • They consume less energy and therefore generate less heat
  • SSDs are more resistant to extreme temperatures, altitudes, vibrations, and shock from dropping the device
  • Less likely to fail or break because of mechanical failure due to their lack of moving parts
  • Lighter and smaller than traditional hard drives because the data is stored at twice the density
  • SSDs' read and write speeds are generally much faster than HDs'.

Disadvantages:

  • Currently SSDs cannot be manufactured with as much storage space as traditional hard drives
  • SSDs are much more expensive than hard drives per gigabyte of storage space
  • SSDs get worn out with increased usage due to the way they write information to different physical locations on the device and fail to completely wipe information that is deleted.
  • They can never entirely reclaim space that has already been used, leading to a shorter device lifetime.

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Applications:

The SSD has many features that make it preferable to a traditional hard drive for many devices. Its lower power usage, which equates to longer battery life and resistance to extreme temperatures, altitudes, vibrations, and shock from dropping make the solid state drive preferable for portable devices and hybrid disks which use an SSD as a buffer for a larger HD. The HD may be spun down more of the time if data is available in the SSD. DRAM-based SSD's may also work as a buffer cache mechanism. In addition, the SSD's resistance to failure or breakage due to its lack of moving parts and lighter, smaller design make them optimal for NAND Flash based SSD's. Microsoft Windows 7 and the Microsoft exFAT file system have been optimized for SSDs and HDs. Recent versions of Solaris, Open Solaris and Solaris Express Community Edition can use SSD drives as a performance booster for ZFS.


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Quick Summary:
While the Solid State Drive has many advantages over HD's, it has several disadvantages as well. SSD's provide higher performance, greater durability and resistance to damage, easier transportation as well as having less of an effect on battery life. However, they are much more expensive than normal hard drives, and wear out faster assuming normal use. For users that require durable storage and have to transfer lots of data, SSD's are a good way to go. However, for most users, HD's are preferable because they will not notice the performance difference, while spending much less money for the same storage space.







Terminology:

  • MLC - Multi-Level Cell technology is a NAND Flash technology using mulitiple levels per cell to allow more bits to be stored.
  • SLC - Single-Level Cell technology is a NAND Flash technology allowing only one bit of data to be stored into each cell.
  • NAND - A type of Flash Memory Technology used in USB thumb drives as well as Solid State Drives.
Related Links:
http://www.anandtech.com/storage/showdoc.aspx?i=3631
http://www.pcmag.com/encyclopedia_term/0,2542,t=solid+state+disk&i=51726,00.asp
http://www.statemaster.com/encyclopedia/Solid_state-drive
www.computerworld.com