Solid State vs Hard Disk Drive

How a Hard Disk Drive Works

Hard disk drives are the parts within machines that are used to store data, they contain circular magnetic disks called platters, these disks are stacked on top of one another, and when the drive is powered on, they begin to rotate at extreme speeds.

Each disk also contains tracks and each track contains sectors, these sectors are where our data is stored.

When we save data onto a storage drive, our data is written onto and retrieved from each sector, and this saving of data is done by what is called an actuator. The actuator is an arm within the hard disk, the tips of the actuator heads sit just above each disk, and upon reading and writing data the actuator arms move on and off the disks. The image below shows the arm on the disk.

How a Solid State Drive Works

Solid state drives are different in the way data is stored, they contain chips known as semiconductor chips, and these chips contain what is known as transistors and other components. On SSD drives, our data is stored within the semiconductor chips and is written onto and retrieved from the semiconductor chips through the solid state drive's embedded processor called the controller.

Unlike hard disk drives, there are no moving parts within a solid state drive which is a huge plus, this increases the speed at which data is stored and retrieved greatly.

Pros and Cons

Capacity - Solid State Drives have now taken the top spot in terms of capacity, up until recent times the largest consumer drive was a 12TB hard disk drive, however, the tables have now turned as Seagate has produced a gigantic 60TB solid state drive, this is something quite remarkable.

Speed - Although one of the fastest hard disk drives (Seagate's Barracuda Pro) spins at 7,200 rpm and has read/write speeds of 250 MBps, it is still slower than most solid-state drives at the moment. A solid-state drive can read up to 10 times faster than a hard disk drive, and in terms of writing data, it can write up to 20 times faster than an HDD, which in my opinion is immense. Solid-state drives are really quick compared to hard disk drives.

Some read and write speeds can get to thousands of megabytes per second. Take for example the Samsung 960 Evo, it can reach up to 3200 MBps read and 1900 MBps write speeds, amazing!

Cost - Hard disk drives are cheaper than solid state drives, at this moment in time a 500GB hard disk drive can be bought for £35.00. On the other hand, the price of solid state drives is a little high, the cheapest 500GB SSD right now can be bought for £120.00, £85.00 more than a standard 500GB HDD. Someone seeking a cost-effective method should of course go for a hard disk drive while a person seeking better performance should opt for a solid-state drive. Personally, for the reasons mentioned already and the coming durability section, I always choose solid-state drives.

Durability - Due to hard disk drives consisting of magnetic disks and mechanical moving parts, their durability is not as good as solid state drives, a 1-meter drop onto a hard surface could result in loss of all data for a hard disk drive. On the other hand, solid-state drives would need a few hard drops before becoming dysfunctional. I have dropped external hard disk drives previously and wish solid-state drives were around then.

Life Span - After researching this subject and from personal experience, it appears that hard disk drives have a life span of around 3-7 years, however, they can last longer depending on the usage and build, and of course fail earlier depending on usage and build. In terms of solid-state drives, the estimated life span currently is around 10 years.

Noise Level - Hard disk drives make noise, solid state drives make no noise at all, if you are after a quiet laptop or desktop you will want to buy one with an SSD storage drive rather than an HDD storage drive. The sound may not seem like too much of an issue, but when you add the hard disk drive noise to the pc fan noise while you are working on something important, it may cause a nuisance.

Power Consumption - Because of the mechanical moving parts within a hard disk drive, naturally power consumption is greater than that of a solid-state drive. When idle hard disk drives consume around 4-6 watts, this can rise beyond 15 watts when active. The amount of power consumed by an SSD is lower than that of an HDD, one example is the Samsung 960 Evo SSD, it requires 5.7 watts when active and only 1.2 watts when idle.

This means a laptop using a solid-state drive may have a longer battery life.