Would overwriting a file with the same exact content have an negative impact on an SSD lifetime?

Question

We are developing a piece of software that does a lot of file overwrites. For the sake of simplicity/performance, we currently don't compare the old file content with the new content that will be overwritten on the disk. So we overwrite files even if when their content is identical.

We run these operations several times a day on a SSD. Does it have a negative effect on SSD wearing ?

Or are modern OS's/NAND controllers smart enough to figure out that the data we're writing is identical to the old one ? (we are targeting Windows based systems)

Answer 1

Short answer. No the controllers do not examine the current file contents before overwriting. That would add significant overhead to a write operation that 99% of time is writing new data.

The good news is that SSDs can actually take a LOT of writes before they die. For some interesting experimental data see the following articles from Tech Report:

Introducing the SSD Endurance Experiment

The SSD Endurance Experiment: They're all dead

Additionally wear leveling mechanisms on SSDs attempt to ensure erasures and re-writes are distributed evenly across the medium (see Wikipedia for more info). So the write operation most likely won't even be going to the same physical location in memory.

However if you can possibly determine that the contents are the same I would suggest avoiding the write. In the end it comes down to performance vs size of data being written.