So what the heck is SSD any way?

I write these articles when I've been asked more than a few times about a particular subject in the tech field. It still never ceases to amaze me when someone asks me about things I think of as common knowledge, but then I remind myself that I'm the one who works in the tech field, not everyone else. Which is why I started this blog to begin with. That being said, lets move on to this article.

You may recall my previous post about Flash (or Thumb) Drives. That memory technology is the leading reason why we even have this great new device. It's read and write speed capabilities, it's ease of use, and it's long term storage capabilities all play a big roll in SSD technology.

SSD stands for Solid-State Disk. Essentially its a newfangled modern version of a computer hard-drive. Its called Solid-State because it has no moving parts. The term SSD has been adopted to distinguish solid-state electronics from electromechanical devices. Since there are no moving parts, solid-state drives are less fragile than regular traditional hard disks and are also silent (unless a cooling fan is used).

There was a few previous versions of SSD's that I should point out. Basically it was a device that used regular everyday computer RAM chips to create a RAM Disk. It would combine all of the total ram chips sizes to create one large storage unit and it would emulate a hard-drive interface to the computer. They were nice because using SDRAM or DDR Ram is extremely fast compared to Flash memory. There are a few drawbacks to this type of SSD though. The biggest one is that because its not flash memory, once the chips loose power, everything that was stored on it is lost, making it completely useless for long term storage. Another is its total capacity is greatly limited. If the largest ram chips on the market are 2gb and there are only 4 slots on the board, then the total drive size will only be 8gb, not a very large drive. Great for the operating systems virtual memory space, but not for data storage. These have been used mostly by specialized computer needs such as enterprise level servers and military systems that move large amounts of data.

The SSD's that is all the rage now is based on Flash memory. Not quite as fast as the volatile memory in RAM chips, but still much faster than its mechanical counterpart. Flash based SSD's have a faster start-up because no spin-up is required. They have fast random access time because there is no read/write head. They have Consistent read performance because physical location of data is irrelevant for SSDs, which also means that file fragmentation has negligible effect. Because they have no moving parts, they are quiet and have a high mechanical reliability, as the lack of moving parts almost eliminates the risk of "mechanical" failure. They have Ability to endure extreme shock, high altitude, vibration and extremes of temperature, lower power consumption, and create less heat, this makes them useful for laptops, mobile computers, and devices that operate in extreme conditions.

On the down side, SSD's are more expensive per GB than traditional hard-drives, but the price of flash memory is dropping drastically making them more affordable to the consumer market. There capacity levels are lower than traditional hard-drives, but flash memory maximum capacities are increasing as fast as the prices are dropping. The physical size of the SSD gets larger as the capacity get larger, so the higher capacity SSD drives are physically larger then traditional hard-drives of the same volume. But I predict that they will overcome this size issue soon as they had to many times in the past with traditional hard-drives.