View from the Hill:- Do CDs and DVDs Have a Long Term Future as Digital Storage?
or are they the future papyrus scrolls of the digital world?

CDs have already been around for 20 years - so that may seem like forever and you may think that DVDs too will still be around just as long. But my own view is that these are merely short term stepping stones to something else in the same way that scrolls and loose collections of paper were a transient phase which gave way to the bound book.

Now when I talk about books - the "transient phase" was hundreds of years and the bound printed books which followed - have been around for about 600 years. Technology changed a lot more slowly in those days. When you're on digital time it becomes hard to recognise the landscape after as little as 600 weeks.

Here are some markers to give you an idea of the rate of change in storage capacity.

RAM Technology

In 1970 the first DRAM chip had a capacity of 1k bits. Nowadays high density gigabyte memory modules are typically made from assembling multiple 512Mbit chips in a single package.

At the individual chip level that's an increase of x 524,288 in 34 years.

If we assume the same rate of increase then by the year 2038 - a RAM chip could store 300 terabytes - and a RAM module will be somewhere between 16 to 64 times as much. This assumes there are no breakthroughs in multi-chip packaging technology - where the real problem has always been heat dissipation rather than the ability of manufacturers to connect dice together and test them and still get acceptable yields and working products.

In reality - semiconductor technology might not be scalable to that extent. But I remember that 15 years ago some people were saying that it wouldn't get as far as it has already done before hitting physical limits. The chip makers already have a 40 year old tradition of proving Moore's law correct.

Hard Disk Drive Technology

In 1984 the typical 5.25" inch hard drives which you could buy for an IBM PC had a capacity of 10M bytes. Today you can buy a 400G bytes drive and fit it in a much smaller space.

At the individual hard disk level that's an increase of x 40,960 in 20 years.

So even in just another 10 years, assuming the same rate of technology improvement - a typical disk drive might have a capacity about 200 times as much as today - or around 78 terabytes. (Trust me on this - it's the square root of 40,960 which gives the right answer.) In practise it might be a little less than 78TB - because the standard disk form factor by then will certainly be well under 1 inch. But why worry? Heck you'll be able to fit a 500TB RAID system inside a little match box.

So where does this leave the transient CD and DVD?

Well, in just the same way that a printed book (with the pages in the right order - but let's not get side tracked into entropy) is much better than a collection of scrolls or loose bound pages, because the unit you're interested in is the whole bible or the whole novel or the entire history book... still with me? - in the same way - an individual CD or DVD is just a fragment of your entertainment and information environment. More like a song or a film scene.

If you can pack the whole entertainment library into a little nugget that's phsically smaller than a CD - then that's what you're going to do. It's tidier and there's less risk of not having what you need when you need it.

In reality advances in communications technology and wireless networking will speed up the process of discarding digital scrolls such as CDs - because they supplement the beneficial effect of oneness, and help speed up the move from scrolls to book.

It doesn't take long to figure out that the storage needs of a typical consumer (movies, music, camera archives, books etc) will be significantly bigger than the amount of data deployed per user by the organisation they work in. (Unless you work or the CIA - or its replacement.) So sometime in the next 5 years the home is going to overtake the office as the biggest repository of storage gizmos and networking.

The computer games market has already shown that the supercomputer processing capacity from one generation can cheerfully be taken for granted as the average kid's plaything in the next. And so it will go for storage too. But on the way - businesses will still have to manage their customers, web sites will still have to deliver the right content. The road will be messy and criss crossed with false turns and blind alleys. That'll be interesting... Stay tuned to STORAGEsearch. You ain't seen nothing yet!