Century IT blog

Hard Disk Comparision – Legacy vs Hybrid vs SSD

January 14th, 2014

The Hard Drive inside a computer is the device that hold all the data and files that makes your operating system run, as well as holding all of your personal documents, photos, music, videos and files.


They commonly look like a solid rectangular lump of metal from the outside, but inside of the average Hard Disk Drive (HDD) is a complex setup of magnets, spinning disks and an extremely precise actuator arm and head.


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The traditional Hard Disk works by using one or more fast spinning (between 4200 -10,000 rpm) magnetically coated platters.


A head on the end of an actuator arm skims above these platters by a miniscule amount. Typically between 3 and 100 nanometres, or a distance 800 times smaller than the width of the average human hair.


The head reads and changes the polarity of blocks on the magnetic coating in order to store data in tracks across the disk as it spins. The time it takes for the head to move to the correct track on the disk to read or write is known as seek time, and in the common desktop Hard Disk, will take around 9ms.


Everything is Stored Magnetically


Because everything is done magnetically, the data is still stored even after power is taken away from the drive.

hard drive internals


Unfortunately, due to the precise and delicate nature of standard Hard Disk Drives, they are all prone to failure at some point and it is inevitable.


Precisely when a drive is going to fail is unpredictable and with storage sizes of the drives being increasingly large (Up to 4TB currently), often a lot of data can be lost within the blink of an eye.


Backing up data is always a good idea, even if the drive is very new, and can save a lot of frustration and anger when it does stop working.


Despite this however, traditional hard disks are used in many computers from new as they offer unparalleled price for the amount of storage they can offer. A 500GB drive can be purchased for as little as £50.


Drives with this sort of storage capacity are often shipped inside of newly bought mid-range computers, and with higher end computers commonly having 1TB and up sized drives.



Solid State Drives (SSD)




Within the past few years, Solid State Drives (SSD) have really begun to take off with more people using them and higher end machines being fitted with them as standard.


Advantages of Solid State Drives include no moving parts, almost completely silent operation, lightning fast performance, cooler operation and durability.



Solid state drives work in a similar way to a USB memory stick or the inbuilt storage in your mobile phone, the data is stored on a flash chip as opposed to a spinning disk. Because there are no moving parts to wait for, the operation speed of a Solid State Drive is often extremely quick when compared to its Hard Disk predecessor and are perfect for high end and performance computer builds.


Solid State Drive Disadvantages

512GB solid state drive (SSD)

Solid State Drives do have their downsides however, and one of these is that should a solid state drive fail, in our experience it will fail completely. It is most likely that whatever data was stored on it will be lost completely.


A traditional hard disk drive often may continue to work long enough after warning of a failure for you to back up any data before it fails completely.


The other main disadvantage behind a Solid State drive, is the cost per GB of storage. This is considerably higher, although constantly coming down in cost.


If you were to attempt to buy a 500GB Solid State Drive, currently you would be looking at spending around 5 times the cost of a traditional hard drive counterpart. The performance difference between the two drives would be immediately noticeable, with the computer starting up far faster, applications loading quicker and files opening in an instant.


Hybrid Drives


There are also Hybrid Drives, or SSHD’s. These drives are fairly limited in variety but are designed to introduce some of the speed of a Solid State Drive with the capacity and cost effectiveness of a traditional Hard Disk Drive.


An SSHD will typically have around 8GB of SSD storage in it which it uses to intelligently pre-cache the most commonly used and accessed files on the systemiStock_000016452360Small


In most cases this will be the operating system boot files, meaning that the computer will start up faster, but may not load programs, games or files any quicker than a normal Hard Disk.


These are however a perfect solution if you can’t afford the cost of a Solid State Drive with the amount of storage space you require.





 Performance Comparison Legacy vs Hybrid vs Solid State Drive 

Avg. Seek TimeTransfer/Write speedCapacityAvg. Mean Time Between FailuresAvg. Cost per GB (500GB drive)
Hard Disk Drive9-12msUp To 200Mb/sUp to 4TB1.4Million Hours£0.07
Hybrid Drive9-11msUp To 200Mb/sUp to 2TB1.4Million Hours£0.13
Solid State Drive0.1-0.3msUp To 480Mb/sUp to 1TB1.5Million Hours£0.46

Century IT Services are based in Totton, Southampton. Hampshire and can help you with the installation or on going I.T support of your computer, server and network. We offer a broad range of I.T services covering, internet, email, anti-spam, anti-virus solutions, we are experts in virtually anything Microsoft Server based and have extensive troubleshooting skills.


If you have an ever growing list of I.T niggles or need a server, or network installed, you have come to the right place. You can contact us on Tel. 023 80 070101 or email us at sales@century-it.co.uk for a confidential, no obligation discussion of your requirements