HDD and SSD Explained

A lot of people are asking the question is getting SSD worth it?  Or should I stick to the traditional HDD.  The big question over which hard drive is right for me is one I will attempt to answer right now.  And try to give as much detail as I can.

A little background

Computer applications to be loaded into memory so they can be used, but when they are not being used they need to be stored somewhere. The storage facility used for all these applications is called a hard drive.  Today there are two main types of hard drives:  Hard Disk Drives (HDD) and Solid State Drives (SSD).


What is a HDD?

These are the drives most people are familiar with and practically all Macs and PCs until very recently ship with them.  They are comprised of one or more plates of magnetic material called platters.  Some are single sided and some use both sides of this platter.  Each platter has a head which  physically moves over the platter as it spins to read and write the data.

You can think of it in a crude way like a record player.  As the platter or vinyl record spins the head or stylus reads the data or music.  The difference is HDD replaces the grooves of a vinyl record with magnetic fields.

HDD speeds refer to how fast the platters spin in the drive.  The most common speeds are 5400rpm (revolutions per minute) or 7200rpm.  Under certain conditions the faster spinning platters allow the head to read and write data more quickly.

What is SSD?

This type of hard drive the new kid on the block. The major difference between with a HDD is that  a SSD uses flash memory with no moving parts to store the data.

General Comparisons

HDD and SSD benchmarks change all the time when new hard drives are released, but there are general trends.

SSDs are on the whole faster than HDDs for most tasks. They can even under certain situations make computers with a slower CPU feel much faster then computers with faster CPU. A good example of this is in the current generation of Mac Book Airs. Everything from transferring files to launching applications to stating up your computer can be faster with SSD.

SSDs are currently the much more expensive option.  Yes in the future SSD prices are likely to fall so it is a case of wait and see what the prices in the future will be.

SDD has a  limited number of times it can read or write a certain section of data.  HDD does not have this issue.  In time the SSD drive will feel slower then it will when it was new.  However for most uses even this slight slow down still leaves the SSD much faster then HDD.

Noise and physical durability of SSD is much better/quieter then HDD.  Simply because of the lack of moving parts in the SSD.

SSD does not suffer slowdown due to a full Hard drive like HDD does.

Which type should I purchase?

Today there are many uses for hard drives, HDD and SSD. and they range to include:

An external hard drive as a backup or storage drive
An external hard drive to constantly work with
An internal hard drive for a new computer
An internal hard drive to replace or compliment an existing internal hard drive.
A raid setup of hard disks – Raid0 and Raid1 being the most common
And there are other uses for hard drives too though they are not all that common.

The general rule of thumb is tasks such as backups and the like suit a hard drive with more capacity which HDD has. And tasks that need raw speed such as multiple file transfers or working on external hard drives suit more SSD. Simply cause SSD has more overall speed then HDD. If you are still unsure, it’s best to get a few 2nd opinions. It can never hurt to be very well informed before a purchase is made.

Just remember to keep in mind that the information technology industry is forever evolving and better and better hard drives are invented all the time. So always check to make sure which hard drive is the best to suit your needs before you make any kind of purchase.