In one of the last pieces I wrote for the Melbourne Herald Sun before a regime change lost me that outlet (that regime has now gone too) concerned a then new solid state hard disk drive replacement from SanDisk. In that piece — written July 2007, three years ago — I wrote:
… the price of flash memory continues to drop. Five years ago the best price I could find for flash memory cards for a digital camera were 256 megabyte Compact Flash (CF): at a cost of $277! That works out to $1.08 per megabyte. The equally popular Secure Digital (SD) format cost more: $1.63 per megabyte at best.
Now, the best prices for reputable brand memory cards are well under three cents per megabyte for both SD and CF, with the former a little cheaper.
In 2002 the biggest solid state memory card readily available was a one gigabyte CF card, at a whopping $1,789. Today you can buy an eight gigabyte CF for less than a quarter of that price — or two 4GB ones for less than an eighth (the largest card sizes usually cost significantly more per megabyte than smaller ones).
Now, three cents or less per megabyte is incredibly cheap … until you compare the prices of hard disk drives. Once again checking prices for reputable brands, the best I could readily find costs a hair over 0.05 cents per megabyte (320GB models seem to be the best value for money at the moment on this basis). Yes, that is one twentieth of a cent per megabyte, compared to flash drives’ roughly three cents per megabyte. Another way of putting it is that each megabyte of space on flash memory costs about fifty times what it does on hard disk.
But five years ago, each flash megabyte cost about two hundred times each hard megabyte, so the gap is narrowing.
So how are things today? Without looking especially hard, I found that you can buy a 1TB USB external hard drive for $95. So the price of a hard disk megabyte has fallen further, to about 0.001 cents, a factor of five in the last three years.
A quick look around gives the most economical flash memory to be 4GB USB at 0.32 centres per megabyte. That makes a flash MB a bit over 30 times more expensive than a hard MB, so the contraction continues, but seems to have slowed in recent times.