There are several different types of backing storage devices with different pros and cons depending on their storage capacity, transfer rate, and portability. Possible storage capacities are forever increasing to keep up with demand, you can now get hard drives with as much as 8 TB or terabytes but unless you know the size of a terabyte that’s not particularly clear.
Hard Drive (Internal / External)
Hard drives are the most popular form of storage, their large storage capacities, low cost, and reasonable durability makes them the perfect choice for manufacturers hence why they come by default with most PCs and laptops. Normal hard drives come in two types, internal hard drives, and external hard drives. Internal hard drives are located inside your PC or laptop and protected by the shell of the machine it sits inside. External hard drives are separate from the main machine and connected via a USB or some other connection because they don’t have the protection of the machine case to sit inside they come inside their own enclosure. Internal hard drives are not typically portable but external hard drives are. They both work in the same way, with platters that spin at various speeds depending on the make and model. Hard drives both internal and external have a rather large storage capacity with the larger ones reaching storage capacities of 8TB and above. A popular Western Digital 500GB hard drive is capable of read and write speeds of roughly 120MB per second.
Solid State Drives (Internal / External)
Solid state drives are becoming increasingly popular as their cost lowers and their storage capacity increases. While they haven’t yet reached the storage capacity of regular hard drives, they are catching up with some solid state drives reaching storage capacities of 4TB. With their slightly lower storage capacities and their slightly increased prices, one might wonder why anybody would choose a solid state drive over a regular hard drive and the answer would be thanks to their massively increased transfer rates. An Intel 240GB solid state drive has a read speed of around four times that of the previously mentioned Western Digital and a write speed of roughly twice the Western Digital. These speeds are achieved thanks to the lack of moving parts found in regular hard drives. The fact that the solid state drive doesn’t need moving parts also means there are fewer ways for it to break increasing reliability. Like with regular hard drives solid state drives can be internal or external with internal not being portable and external being portable.
Flash memory comes in many forms, the two most common being a USB drive, also known as a pen drive, or flash memory cards, the most common being SD cards often used in cameras. These seemingly different devices actually work in pretty much the same way just with different cases and connections depending on the device they need to connect to or slot inside.
While the storage capacity of these types of devices is historically not great they are improving with some USB drives reaching as much as 128GB. However, their true strengths lie in their amazingly low costs, their increasing speeds, and reliability and the fact that they are easily the most portable type of backup device with most USB sticks being able to fit on a key ring. This SanDisk USB drive also has faster read and write times than the previously mentioned Western Digital hard drive.
Commonly known as CD’s or DVD’s, they are not very reliable being easily damaged and having a fairly short lifespan. Their storage capacity is not great with single sided DVD’s being capable of 4.7GB and double-sided DVD’s being capable of 9.4GB. Their read and write speeds are also incredibly slow compared to previously mentioned backup devices as can be seen by this table:
With their poor transfer rates and low storage capacities, it can be easy to dismiss optical drives as useless. However, their extremely low cost and ease of portability make them a very popular distribution method for companies as their low cost makes them expendable.
Floppy disks are virtually extinct in this day and age, these magnetic disks inside protective cases are more used by reminiscent fans for their retro feel than for any practical use, most computers today don’t even come with the floppy disk drive by default. Their incredibly low storage capacity of around 1.44MB pretty much limits you to simple word documents and small spreadsheets and their low transfer rates of around 500KB per second would keep you waiting for those documents.