"As a sanity check - I found some data from Mtron (one of the few SSD oems who do quote endurance in a way that non specialists can understand). In the data sheet for their 32G product - which incidentally has 5 million cycles write endurance - they quote the write endurance for the disk as "greater than 85 years assuming 100G / day erase/write cycles" - which involves overwriting the disk 3 times a day."
That was written in 2007. SSD flash cell life has increased substantially in the 3-4 year period since. Stan you are wrong on that... flash cell life decreases when they shrink process in which they are made.
With the new generation of 25nm flash it's down to 3000/programming cycles. So the drive manufactures have to battle that with increasing a ECC length and better wear leaving. Or if I quote anand "When I first started reviewing SSDs IMFT was shipping 50nm MLC NAND rated at 10,000 program/erase cycles per cell. As I mentioned in a recent SSD article, the move to 3xnm cut that endurance rating in half. Current NAND shipping in SSDs can only last half as long, or approximately 5,000 program/erase cycles per cell. Things aren’t looking any better for 25nm. Although the first 25nm MLC test parts could only manage 1,000 P/E cycles, today 25nm MLC NAND is good for around 3,000 program/erase cycles per cell.
The reduction in P/E cycles is directly related to the physics of shrinking these NAND cells; the smaller they get, the faster they deteriorate with each write."
Please read the article on annandtech [1]
1 - http://www.anandtech.com/show/4043/micron-announces-clearnand-25nm-with-ecc
Regards, Miha