[citation][nom]rosen380[/nom]"Welcome to technology where things move in logrithmic accelerating fassion."Since when?[/citation]
I think you're confused about the meaning of linear vs exponential growth. And the growth is assuredly exponential.
Linear growth would be if it grew by the same fixed NUMBER (not percentage) every x number of years.
For example: If the storage capacity in 2005 was 500GB, and in 2007 it was 1TB, in another two years, it would be 1.5TB, another 2 years 2TB, and so on (growing by a fixed 500GB every two years).
Instead, the storage capacity is DOULBING every two years. 500GB in 2005, 1TB in 2007, 2TB in 2009, 4TB in 2011.
Linear = flat rate growth, Exponential = growth that changes in rate.
Sure it's growing by 100% every two years, but that doesn't mean it's a fixed rate, since that percentage is compounded every period.