Does deleting stuffs off your SSD lowers its lifespan?
When you delete stuff, there's just some bytes changed, adding some records to a list, telling the ssd controller "these blocks of flash memory can be erased and made ready for new writes"
That erasing process causes wear on the flash memory and after a lot of erases, that memory area becomes read only, can not guarantee it could store new data reliably.
Think of the flash memory arranged in 24 MB or 32 MB or 64 MB chunks, each chunk having lots of 512 byte or 4096 byte "pages" - the SSD controller can write a random page in one of these chunks, but can't overwrite it. It also can't erase an individual page, it must erase the whole chunk.
So when you write stuff to the SSD, the SSD controller finds empty pages in random chunks of flash memory and puts data there, trying to spread it across a lot of memory chips, to get faster write speeds by writing in parallel into multiple chips (or layers of a chip)
If you want to overwrite data in one of those small 512-4096 byte pages the SSD controller can't overwrite, so it just finds another available page in some random chunk, reads that data from the old page, makes the changes, writes the data in the new page and marks that old page for deletion.
From time to time or when it needs free space to write new stuff, the SSD controller looks at chunks and where it finds a chunk with let's say 90% of its pages marked for deletion (having old data), it will copy the pages that still have valid data to other chunks and then erase the whole chunk to make the whole chunk available for writing again ... and by doing that erase, the whole chunk is now a bit more worn out.
So basically , on a new 250 GB drive, you could write 200 GB of movie, erase those 200 GB, and the drive's health would still be 100%, because the controller didn't actually erase any chunk yet, the content is just marked as "can be erased when needed".
When you write another 100 GB, the controller will write 50 GB in the cells that were never used so far and then it will have to erase some chunks to get another 50 GB of free disk space. So after writing 350 GB of data, you would have 50 GB worth of memory chunks erased once, and the rest of 200 GB never erased.
With TLC, you have 1000-3000 erases and then the memory chunk is done for.
Modern SSDs use a portion of the flash memory chips in pseudo-SLC mode, where each cell of memory holds only 1 bit instead of 3-4 bits in the case of TLC or QLC. By using this mode, these chunks can be erased more "gently" and this pseudo-SLC portion can do even 10-30k erases before it's worn out completely.
So if you have content that only stays on the drive for an hour or so, the SSD controller may not even move the data from the pseudo-SLC write cache area into "permanent storage". If this happens , the consequence of erasing the data from pseudo-slc cache is less serious, it does less damage to the cells in theory.
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