Feeds

Why data storage technology is pretty much PERFECT

There's nothing to be done here... at least on the error-correction front

Gartner critical capabilities for enterprise endpoint backup

All present and correct

Without the combination of reliability and storage density it allows, the things we use every day simply wouldn’t work. The images from our digital cameras would be ruined by spots that would make us prefer the grain of traditional film. Our hi-fi would emit gunshots making the crackles of vinyl infinitely preferable and the supermarket barcode reader would mistake the lady in the tweed coat for a tin of baked beans. And whether you could call flash cards or discs compact if they were a metre across is another issue.

Oversize DVD writer

How "compact" optical media might have emerged without Reed-Solomon error correction

With the help of error correction, recording densities will keep increasing until fundamental limits are reached. The flash memory using one electron per bit; the disk where one magnetised molecule represents a bit; the optical disc that uses ultra short wavelength light. Maybe it would be called Gamma-Ray. Or a quarkcorder called Murray. More likely storage capacities would level out before those limits are reached. When storage costs are negligible there is no point in making them more negligible.

Making do with perfection

Information theory, first outlined on a scientific basis by Claude Shannon, determines theoretical limits to the correcting power of a system in the same way that the laws of thermodynamics place a limit on the efficiency of heat engines.

However, in the real world, no machines reach the theoretical efficiency limit. Yet the Reed-Solomon error-correcting codes actually operate at the theoretical limit set by information theory. No more powerful code can ever be devised and further research is pointless.

The degree of perfection achieved by error-correction systems is remarkable even by the standards of technology. I suspect this is because the theory of error correction is so specialised and arcane that politicians and beancounters have either never heard of it or daren’t mess with it and it is left to people who know what they are doing.

In contrast, anyone can understand water flowing in a pipe and that is why our drinking water system is in such a shambles - with much of it running to waste through leaks.

Although the coding limits of error correction have been reached, that does not mean that no progress is possible. Error correction and channel coding both require processing power to encode and decode the information and that processing power follows Moore’s Law.

Thus the cost and size of a coding system both diminish with time, or the complexity can increase, making new applications possible. However, if some new binary data storage device is invented in the future using a medium that we are presently not aware of, the error correction will still be based on Reed-Solomon coding. ®

John Watkinson is a member of the British Computer Society and a Chartered Information Technology Professional. He is also an international consultant on digital imaging and the author of numerous books regarded as industry bibles.

Secure remote control for conventional and virtual desktops

More from The Register

next story
The Return of BSOD: Does ANYONE trust Microsoft patches?
Sysadmins, you're either fighting fires or seen as incompetents now
Microsoft: Azure isn't ready for biz-critical apps … yet
Microsoft will move its own IT to the cloud to avoid $200m server bill
Oracle reveals 32-core, 10 BEEELLION-transistor SPARC M7
New chip scales to 1024 cores, 8192 threads 64 TB RAM, at speeds over 3.6GHz
US regulators OK sale of IBM's x86 server biz to Lenovo
Now all that remains is for gov't offices to ban the boxes
Object storage bods Exablox: RAID is dead, baby. RAID is dead
Bring your own disks to its object appliances
Nimble's latest mutants GORGE themselves on unlucky forerunners
Crossing Sandy Bridges without stopping for breath
A beheading in EMC's ViPR lair? Software's big cheese to advise CEO
Changes amid rivalry in the storage snake pit
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.