What are SSDs?
SSD stands for solid-state drive. Some people use the term solid-state disk, but that’s a bit of a misnomer since SSDs don’t use disks. Instead, solid-state devices rely on integrated circuit memory technology.
Manufactured by StorageTek, the STC 4305 hit the scene in 1978 and is considered the first SSD. A technological marvel of its time, the STC 4305 was seven times faster than HDDs and cost half the price.
In time, engineers switched to a dynamic random-access memory protocol, and by the late 1980s Zitel Inc. was offering DRAM-based products marketed as “RAMDisk.” The first laptop to incorporate SSD technology was IBM’s ThinkPad in 1991, which included a 20 megabyte SSD developed by SunDisk Corporation. Today, some SSDs achieve speeds of 3500 megabytes per second.
Solid-state drives are called such because they don’t have any moving parts, making them more reliable than their HDD counterparts.
How Do SSDs Work?
Solid-state drives are comprised of semiconductor flash chips arranged in an integrated circuit grid. Grids are divided into sections called “pages” where data is written and stored. Pages are further configured into “blocks,” which represent groups of information.
SSDs do not require revolving disks or actuator arms to initiate a process. The actual SSD technology is similar to RAM. However, unlike RAM, data written onto a solid-state drive remains even in the event of a power loss.
What are HDDs?
HDD stands for hard disk drive. HDDs use magnetic storage technology in conjunction with rotating platters and an actuator arm to write new data and retrieve stored information.
International Business Machines (IBM) invented HDD technology back in the 1950s. A near instant success, hard disk drives quickly became the preferred method for digital storage. In those early years, when computers were the size of large lockers, HDDs were gigantic. Over the decades, however, they’ve hued to Moore’s law.
How HDDs Work
HDDs contain an actuator arm fitted with a read-write head, one or more magnetic platters and a motor. They’re also equipped with an I/O controller and firmware that facilitates communication with the rest of the computer.
Each of the magnetic platters is comprised of concentric circles called tracks. Tracks are further divided into sectors, and algorithms handle data processing.
On consumer computers, the platters typically spin between 4200 rpm and 7200 rpm. The higher the speed, the faster the drive can read and write data.
To SSD, or HDD, That is the Question!
Whether or not an SSD or HDD is the better option is situation dependent.
If Speed is Important
People most concerned with speed usually prefer an SSD-equipped system, as they run about 100 times faster than HDD machines. SSD desktops and laptops boot up significantly quicker than comparable systems fitted with hard disk drives.
Keep in mind, however, that SSDs do get slower over time.
If Durability is Important
Other SSD benefits include its lack of moving parts and the ability to withstand rough treatment. For example, if a laptop is being used at a construction site where the likelihood of being knocked over is high, it’s probably best to opt for the more durable SSD option.
If Preserving Battery Power is Important
If you rely on battery power, an SSD is your best bet since they use significantly less power than their HDD cousins.
If Price is Your Top Priority
You may be reading this and thinking: SSDs seem better in every way. Why on earth would I opt for an HDD? But here’s the rub: HDDs are significantly less expensive than SSDs. So if budget is your biggest concern, then a laptop or desktop that uses a hard disk drive will be your best bet.
The Non-Techie Difference between Solid-State Drives and Hard Disk Drives
An easy way to remember the performative difference between a solid-state drive and a hard disk drive is to think of them as iPods and record players. SSDs are comparable to iPods and HDDs to record players.
SSD v. HDD: A Comparative Performance Chart
|Performance Consideration||Solid-State Drives||Hard Disk Drives|
|Access Time||Access time rates on SSDs are as close to zero as humans can comprehend.||Access time rates on HDDs run between five and a half and eight milliseconds.|
|I/O Performance||SSDs deliver, at the minimum, 6,000 IO/S, which is about 15 percent faster than what an HDD can deliver.||HHDs I/O performance typically comes in at around 400 IO/S.|
|Reliability||Solid-state drives enjoy a failure rate of less than a half of a percent.||Hard disk drives have a failure rate range between two and five percent.|
|Energy Savings||SSDs use between two and five watts.||HHDs use between five and 15 watts.|
|CPU Power||On average, solid-state drives have an I/O wait of about one percent.||On average, hard disk drives have an I/O wait of about seven percent.|
|Input and Output Request Times||Service time for an I/O request while running a backup is typically 20 milliseconds or less.||Service time for an I/O request while running a backup is typically between 400 and 500 milliseconds.|
|Backup Rates||On a computer with a solid-state drive, backups take about six hours.||On a computer with a hard disk drive, backups take between 20 and 24 hours.|