SSD stands for solid-state drive, and the acronym is used to differentiate it from the traditional HDD or hard disk drive. HDDs have been around since before the personal computer but didn’t become cost effective until the before the personal computer but didn’t become cost effective until the early years of the PC. The first PCs shipped only with floppy drives, but a few years later, 10MB hard drives came on the market, and the size has been growing ever since. Today it is not unusual to buy a new computer with a one terabyte (TB) drive or larger.
There have been two problems with hard drives since the beginning reliability and speed. Since they were made up primarily of a spinning disk and a moving head, they were, by design, fragile pieces of equipment. Hard drive failures, while not as common as they once were, are still a problem. Once a hard drive crashes, recovering the data from it is difficult and expensive.
The second problem is speed. Two factors cause this. One, the disk needs to each a certain speed before the head can track and find the data, and second, the data can become fragmented with pieces of it scattered all over the disk. The head has to hunt to find all the pieces and put them together. Programs to optimize and defrag the drive take a long time to run.
SSDs, are similar to the technology found on thumb drives, but the type of memory used is much faster and more reliable, allowing the practical limit in storage size to become much larger. There are no moving parts to an SSD. Currently, there are 4 TB SSD drives on the market but that size is very cost prohibitive. As with any technology, there is a tipping point where size vs cost become practical.
SSDs began appearing in laptops in the early 2000s, but sizes in the 1 and 2 GB range didn’t start showing up until 2007 By that time, hard drives of 500GB weren’t uncommon, so there has always been a gap in the practical storage size of the two mediums. As memory has become cheaper and SSDs efficient, SSD prices for up to about 1 TB drives have dropped to about double of that of a comparable HDD. At that price point, performance for the money makes them very attractive.
Because there are no moving parts or a disk that needs to be brought up to speed, computers with SSD drives boot very quickly, and programs load almost instantly Also, the issue of fragmentation isn’t as significant since there is no head that has to jump around looking for the data. Defragmentation not only becomes less necessary, but if needed, will run much faster. Finally, as there are no moving parts, reliability is much less likely to fail.
Image: SSD/HDD Hybrid + HDD by Yutaka Tsutano