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Index

• History of the Hard Disk Drive
• Hard Disk Drive Technology
• Other technology
• At last the bottleneck is resolved by SSD hard disks
• The future
• Software Benefits

History of the Hard Disk Drive

SSD hard disks have been around since 1980 when Seagate Technology introduced the 1st hard disk drive for microcomputers called the ST506 with a 5 megabyte capacity and costing over $1000 back in 1980 (a small fortune). (see http://www.duxcw.com/digest/guides/hd/hd3.htm for more info).  The world's 1st gigabyte-capacity disk drive (the IBM 3380) introduced in 1980 was the size of a refrigerator, weighed 250kg and cost  $40,000. A lot has happened to the hard drive since those days, but in 1997 Seagate introduced the first 7200 rpm drive using an Ultra ATA interface and later on in the same year a 15,000 rpm drive using IDE DMA and ATA/33 and ATA/66 interfaces.

Hard Disk Drive Technologytop

Current hard drives have an electric motor rotating a magnetic platter with a head that sits very close to the magnetic platter (measured in micro-inches).  The rotating head reads a magnetic state of either on or off on sections of the platter which is how the data is stored.  Those sections are very small and allow the drives to reach a very large capacity.

ATA/33 capable of 33.3 Megabits per second ATA/66 capable of 66.6 Megabits per second Ultra ATA/100 capable of 100 Megabits per second Ultra ATA/133 capable of 133 Megabits per second SATA 150 capable of 150 Megabits per second

The term IDE(Integrated Drive Electronics) is owned by Western Digital and most other companies use the term ATA (AT Attachment) but both IDE and ATA  mean the same thing. PATA (Parallel ATA) is the term used to describe the grey wide 80-pin cables we are used to seeing inside our PC's to connect our hard drives and CDROM drives,

SATA or Serial ATA (Advanced Technology Attachment) is the next generation of drive interface to replace Parallel ATA (PATA).

SATA hard drives and CDROM drives use a thinner more flexible 7 pin cable which helps with airflow and cooling within the PC.  The interface is capable of 150 Megabits per second.

This Megabits per second measurement is the capacity of the interface to pass data to and from the drive. 

Other Technology top

Currently a drive running in a 24/7  operation will typically last around 3-5 years before failure.  Much the same as moving parts in any device will eventually fail.  Because of this RAID systems were developed to ensure contingency on failures.  This enables the use of 2(or more)  drives mirrored together (storing identical data on both(or multiple)  drives) so that WHEN one drive fails  the data can be retained by replacing the failed half of the pair (array).

RAID systems have evolved to not only allow for failures but to also increase the speed of reading and writing data to drives. 

Because of the slow rate of access to data on spinning drives, RAID enable systems to access data faster by sharing the reading and writing of data across the 2 (or more) drives simultaneously.

Whole Backup systems have been developed and millions is spent by businesses  to ensure that the failure of a Hard Disk is not catastrophic to its business.

Therefore the Hard Disk Drive has been both a brilliant invention but has been inherently flawed.  Technology has developed around it to solve it's problems and failures.

At last the bottleneck is resolved top

PC technology has grown very fast in terms of speed and power, but the design of the Hard Disk Drive has changed very little.  Processors have gained an unprecedented growth in speed and power to the extent where we now have Quad Core processors  and ultra fast graphics cards with Gigabytes of RAM.  Yet the Hard Disk Drive design has remained the same, with it's failure rates and low access speed.

We are lured into buying the latest and fastest processor to give us ever faster PC systems, yet the design is based around the slow and ultimately vulnerable spinning Hard Disk Drive.  No matter what technology has been developed in the past – it is based around a technology that would never reach a speed that would match it's potential based on the spinning Hard Disk Drive.  No matter  what progress was introduced, a compromise would always be made with this technology.

The Future top

With Solid State Disk technology, we no longer have a technology that is prone to failure, that has a limit to it's access time based on the laws of physics.  Solid State Disk technology will allow read and write times to reach the maximum BUS speeds, this will significantly improve computer processing.

Solid State Disks also use a lot less power and generate virtually no heat.  Large enterprise  installations of huge server farms exist in most large companies, with huge amounts spent on cooling, backup generators and UPS systems for power outages.  With less power used, less heat generated, this will reduce the investment needed for such infrastructures.  This will save companies vast amounts of money year on year in operating costs and investment.  A Solid State Disk uses 95% less power than physical hard drives in idle mode and 50 to 85% less power when in use.  Therefore each SSD can save up to 21.9 Kilowatt-Hours of power per year over a physical drive.  In today's clamour for environmentally friendly operations, this is a major step forward.

These benefits have a knock on effect on the rest of the computer's parts.  With less heat, comes less cooling required, this will enable the pc or server to have a slower fan for cooling which will generate less noise.

Software Benefits top

Software can now be freed of the restrictions based around a slow access time of a physical disk, freed from the bottleneck of retrieving and writing data.

Taken directly from http://www.mysql.com/products/database/cluster/

Here we can see that a software product has solved it's IO bottleneck issue by using the server's RAM instead of it's Hard Disk.  Whole areas of technology have been designed around the physical restrictions based around the physical disk.

This is just a tip of the iceberg - only time will tell before Solid State Disk technology completely replaces the existing one.

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Available as a PDF to download

Created by the team at www.futurestorage.co.uk