Quote:
Originally Posted by RickS
Here's a significant study of SSD reliability (6 years, many drives):
http://0b4af6cdc2f0c5998459-c0245c5c...-schroeder.pdf
tl;dr: SSDs have a much lower replacement rate than HDDs but are more likely to develop uncorrectable errors and bad blocks. Usage is not as big a factor in SSD failure as expected but age is significant.
SSD drives are based on NAND flash, and NAND flash blocks wear out after being written too many times (technically, they have a limited number of program/erase cycles.) The SSD controller does wear levelling to spread write activity evenly over all the physical blocks. By comparison, writing to a HDD block doesn't cause any wear though the mechanical nature of HDD drives means that they wear out over time as well.
In normal use it will take you a very long time to exceed the number of P/E cycles for a modern SSD drive (and as the paper linked above finds, the failure rate doesn't get dramatically worse when you do). Unless you are writing very large amounts of data very frequently I wouldn't worry about it.
Cheers,
Rick. |
This is correct ....
Also different SSD HDD's are manufactured to optimise different read and write lifecycles to suit different usage patterns.
So you should choose your SSD very carefully.
Another consideration is O/S and the O/S filesystems.......the latest version of Mac OS has a new filesystem APFS which specifically caters for the unique nature of SSD storage.....but not all O/S's work as well with SSD to extend the lifetime & reliability.
If I had to buy a new SSD today it would be the new Intel 3D XPoint technology drives.