Hard Drives vs Solid State Drives

Both store your files, but they are drastically different.

While preparing an estate sale after my father recently passed; I came across a box of unused floppy disk drives that he had saved. They brought back memories to my college days and early programming jobs decades ago when I regularly used them for backups or to transfer files between computers. Today, you can rarely find an old drive that will let you access one of these disks. I threw the box away; knowing that even a donation center would not want them.

They have been joined in their demise by a variety of other antiquated data storage devices. Things like Zip drives, CDs, and DVDs may not be extinct; but they are certainly on the endangered species list for data storage. These days, almost all data is stored on a hard disk (HDD) or on one of the many storage devices containing flash memory chips. The Solid State Drive (SDD) is the most common of these devices now. Affordable units in 1 TB, 2 TB and 4 TB capacities are available, with even larger capacities available if your budget allows.

Both HDDs and SSDs are ‘block’ storage devices. This means they present themselves to the host computer as an array of equally sized blocks (usually 4096 bytes in size) that can be used to store data. A file system running on the computer is responsible for keeping track of which blocks on the device belong to any given file and in which order. Firmware on the device itself can rearrange individual blocks when it detects flaws in the media or to prevent excessive wear; but this is done independently of the computer software.

While all block storage devices might seem the same to a given file system; HDDs and SSDs are fundamentally different in terms of their speed, durability, and costs. Hard drives contain rotating disks with read/write heads that must be positioned for every disk access. Their mechanical nature means there is a very physical limit to how fast they can operate. The fastest drives available generally fall into the 200 MB/s to 300 MB/s range.

SSDs, on the other hand, have no moving parts. Even the slowest SSD will easily outpace the fastest HDD. The best SSDs are now about 50x faster than the best HDD. This makes them ideal for storing data that is accessed frequently like operating system and program files. Recent improvements in their capacities have enabled computers to be shipped with only an SSD without worrying much about running out of disk space.

While SSDs have come down significantly in cost; they continue to be more expensive than HDD space. They used to cost 10x or more per terabyte than HDD, but now they are only about 3x - 5x more expensive. Time will tell if they will eventually meet parity or even surpass HDD in terms of cost; but for now extremely large data sets are most likely to be stored on good ‘ol hard drives. Cloud providers have massive racks of hard drives currently in data centers around the world. The demise of hard drives has been forecast for some time; but HDD manufacturers continue to defy those predictions.

The basic question for the average user is ‘How much space to I really need?’ when determining which storage devices to purchase. If the entire data set (OS, programs, documents, pictures, and other data) fits within a few terabytes; then SSDs can most likely fit your needs. If, on the other hand, the data set consists of a dozen or more terabytes; then a HDD is probably the best option.

Regardless of which underlying storage devices are chosen; good practices are needed to protect and access all that data. Regular backups, fast searching techniques, and other maintenance will help avoid lost files and lost time. Other tools are available to help with this; but Didgets was designed to make data organization, search, and access as quick and painless as possible.