Solid State Drives for Dummies
Next-Gen Data Storage
Who doesn't love new data storage technology? OK, maybe the majority of computer users just don't care, but here are a few of reasons why they should, and perhaps why you should. A Solid State Drive (SSD) behaves just like a hard drive, but on the inside it's completely different.
How it Works
First of all, an SSD has no mechanical parts whatsoever. If you are familiar with conventional hard drives, you may know that they read to and write from rotating magnetic platters – or disks. Sort of like a CD or DVD but much faster and without the lasers. Because of the mechanical parts and the tiny areas available for reading and writing, hard drives are very fragile. Usually, the hard drive is the first thing to break in a computer.
A Solid State drive, on the other hand, uses memory technology that works more like the computer's internal memory (RAM). But unlike RAM, where information is only stored temporarily and disappears as soon as it loses power, an SSD retains its data even when your computer is turned off. In addition, it does all this without involving mechanical arms, rotating platters or anything else that could easily break.
Instead of employing decades-old magnetic storage technology, SSDs use so-called Flash memory that holds the data even if it’s not connected to a power source. You may be familiar with Flash memory from the memory cards in your digital camera or mobile phone – this is exactly what the technology is about, only a solid state drive is a bit more complex.
Different SSD Solutions
Without going into overly complicated details, there are two types of Flash memory technologies used in SSDs. Flash memory is based on memory cells, and the most common (and most affordable) type is the MLC (Multi-Level Cell) – a technology that enables writing more data to a single cell of the drive. Then there’s the SLC (Single-Level Cell) that only writes one bit of data at a time. SLC drives are more common in servers, since their performance is often better and they can withstand more writes before wearing out.
Most SSDs aimed at the consumer market is the type of MLC that wears down faster, meaning that you can’t expect your new drive to last forever. However, it will still withstand enough normal use that this is hardly a problem in the real world – most likely it will outlast a hard drive several times over and be one of the last things to break in your computer.
First and foremost, SSDs are much, much faster than hard drives. With today’s fast processors, RAM memory and other components, the hard drive has become the major weakness in a modern computer. Every time you load applications, games or start up the operating system, the hard drive is the bottleneck that slows down operations.
Shifting to a fast SSD will bring tremendous performance benefits to any modern laptop or desktop PC, including significantly reduced startup times, faster load times, as well as speed up working with large files like pictures and video. One of the reasons for this improvement is that it can read and write to many different parts of the Flash memory simultaneously, in parallel operations.
An SSD does not have to wait for things to move (such as a mechanical arm to reach its designated area on a disk,) and this gives it a huge advantage in terms of access time – the time it takes from when your computer asks for data to be read or written to that task actually taking place. To put it simply, access times are almost eliminated completely compared to hard drives.
Because an SSD doesn’t spin, it also uses less power than a regular disk, although it’s worth mentioning that portable hard drives have made great strides in power efficiency in recent years. Still, a 2.5-inch mechanical disk uses marginally more power than a solid state drive.
The major disadvantage so far is that SSDs are much more expensive compared to conventional hard drives. You have to pay more for less storage space, so you will have to compromise between storage space and speed. Prices continue to drop as the technology becomes more mature, but the difference in cost is still large. Due to the continuous development of new hardware, it’s always a good idea to read SSD reviews before making a purchase.
Important: Never Defragment Your Solid State Drive
Reading or writing to a rotating disk is faster when it is done sequentially, i.e., the data should be located in a row on the platter so that the drive’s head doesn’t need to move around too much to read the subsequent parts of your files. Therefore it is normal to collect fragmented files and arrange them into adjacent areas of the disk. This is called defragmenting.
In an SSD, it is perfectly normal that data is spread around across different areas of the drive – in fact it is beneficial, since it reads data in parallel from different locations to improve performance. Defragmentation would mean unnecessary wear and tear on the drive. Modern operating systems will recognize if a solid state drive is installed and disable defragmentation, but older ones will not so it may have to be disabled.