The other interesting observation in the article is that there is a floor price for hard drives - there is a bare minimum cost for the mechanism that doesn't reduce if you make them smaller. If (as seems very likely) they also spotted the trend, they had 2 options: get into SSDs early (a few did) or push the improvement rate of HDs to match DRAM - which happened in the late 1990s. Obviously disk manufacturers also have smart people working for them and didn't want to be put out of business. So why aren't we all using FLASH drives, with disks relegated to museums? The price trend is approximately the same as that of DRAM. Even if FlASH is more expensive per bit than DRAM, taking away the need for power means it's a viable alternative to disk and the crossover point wouldn't have moved that far out. Of course an solid state disk (SSD) can't be made out of DRAM without a robust power source FLASH has fixed that problem. In the 1990s, in my advanced computer architecture course, I demonstrated that the price trend of hard drives was going to intersect the price trend of DRAM at around 2004 to 2005.

Here is an interesting article on SSD vs.

Solid state drive for macbook air