23 March 2007

TeraBytes at Home

I just purchased a 1TB external disk from LaCie for about £230 (ex VAT). This will be primarily used for backups at first and directly connected to our laptops. Longer term, I may use it as a NAS-type device (a networked disk perhaps using Apple's AirDisk). But the 1TB figure seemed pretty monumental to me, and got me thinking back to how quickly this has developed.

A few years ago after an article in the Independent by "Cursor" claiming that disk drive technology had seen 200 times compound growth, I checked their calculations (which were wrong) and showed that in fact, disk drive size had doubled approximately every 11 months versus chip technology which had doubled every 18 months (the infamous Moore's Law). I got a quick reply and correction from Cursor (Charles: are you listening) admitting a rushed job on doing the exponentials.

We all agreed nevertheless that doubling every 11 months had been phenomenal and was still 63% better than chip technology. I think since that time disk drive technology might have slowed a small amount (though chips have continued to develop along Moore's Law lines, albeit with a slowing down in clock speed advances). Of course, at this time, the real star is NAND Flash storage that is growing at a faster rate than either.

But 1TB at home seems just amazing. To put that in a few perspectives:

- 1TB for £230 is equivalent to 23pence per GigaByte, or just .023 pence per MegaByte.
- 1TB is 12,500 times an 80MB disk (that was the size of my first major disk purchase (for a Mac II in 1998 which cost more than this).
- 1TB disks come in a size no bigger than the 80MB disks of old, and are also better in every other respect - power, seek time, reliability, transfer time, noise etc.

That is some achievement. Interestingly, the transfer time of this disk in Firewire800 mode is such that it can transfer over 80MB in one second, which is conveniently equal to the full size of my first hard disk!

Of course, back in the 80's nobody would have thought that the average consumer would require terabytes of data storage. But with uncompressed storage of music, storage of our digital photo collection, and increasingly video storage, it is quite easy to see 10TB being necessary in the not-too-distant future. What about the 1PetaByte home? That is 1,000, million, MegaBytes! Is it really that far off?

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1 comment:

Charles said...

I'm sure the article had my name on - I was making a similar point about growth and comparing it to the 20MB in my first computer (nyah). But yes, instead of doing the compound form, I rushed the calculation and divided instead. Tch.

And I think that I also corrected it next week. Journalists correcting things? Honestly, where will it all end?