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Peter Cochrane's Blog: Thanks for the memory
Remember when 20MB cost $20,000?
22.06.05, 20.15 GMT, A coffee shop in London, UK

When I was 29, I was given the job of buying some computer memory. In those days buying any kind of equipment was a big deal - but memory was one of the biggest. After chasing the few suppliers and leaning on the good customer, I managed to get a bargain, a full 20MB for a mere $20,000!

Just 30 years on and I can now purchase 250GB for around $120. So the price per MB has fallen from $1000 to around one half of a penny - four orders of magnitude in three decades.

This incredible progress has changed just about everything. We now build-in memory to displace other functions such as raw processing power and time. Memory was once so expensive we spent a lot of time trying to design it out. It was also big. My 20MB Winchester drive had five platters the size of dinner plates in a box the size of a pilot's flight case. Today's equivalent fits in my jacket pocket, makes a lot less noise, consumes a lot less power and has an incredibly fast read/write rate and access time.

My youngest son has trouble contemplating a world without computers and low-cost everything. Almost without a thought he set about building a one terabyte (1000GB) storage unit a few years ago, which he has now migrated to become a three terabyte server. I suspect this is more memory than was available in the entire UK 30 years ago!

As I look forward I now covet an unusual ambition: to assemble a one petabyte server before I expire. For perspective, 1 petabyte = 1,000 terabytes = 1,000,000 gigabytes = 1,000,000,000 megabytes.

What a lot, you might say, and how would I ever fill it? Funnily enough, that is what I said when I was 29. But now I have 100GB of hard drive space and 2GB of RAM on my laptop, and there is only about 30 per cent to spare. How come? I never delete anything, just like companies which are inclined, if not forced to do the same for regulatory and/or legal reasons.

The good news? We have technologies to continually increase bit storage density for many decades. The bad news? We will find the means to fill it! And the price? It will keep falling as will device size. In theory I can already afford to store a digital Library of Congress in my home plus every movie and music track ever produced - but not the entire internet.

The next 30 years are going to be a lot of fun and I reckon my one petabyte will be reached within 20 years if I can make it. For my children it is a given!