Naked Science Forum

Non Life Sciences => Geek Speak => Topic started by: syhprum on 27/08/2018 17:10:50

Title: How much damage does formatting cause to SSD,s
Post by: syhprum on 27/08/2018 17:10:50

We are cautioned not to format SSD,s but when they are infected by persistent malware the temptation is there to do so, to what degree does the occasional format damage them.

Title: Re: How much damage does formatting cause to SSD,s
Post by: chris on 27/08/2018 17:32:00

Very good question - I'm glad you asked because I'm wondering the same thing. I did a "fresh start" on a windows surface laptop (with a 256GB SSD) yesterday; as part of that I decided to wipe the free space in case there was anything lurking there; I used CCleaner, which is my go-to workhorse for this sort of thing and, before starting, it cautioned me against wiping this sort of drive suggesting that doing so shortens the lifetime of the SSD.

I am confused by this. My OS is presumably reading and writing data from / to the SSD regularly - so why should overwriting the drive with random characters once cause harm?

Can someone please elaborate?

Title: Re: How much damage does formatting cause to SSD,s
Post by: syhprum on 27/08/2018 17:51:20

I use Diskeeper that diverts a lot of of writes and reads to RAM and I have not noticed any deuteriation in my SSD,s as yet so I too look forward to an expert opinion.
Also I consider their speed to be adequate to cope with power off shut downs that with my PSU,s holds up for about 2 seconds

Title: Re: How much damage does formatting cause to SSD,s
Post by: evan_au on 27/08/2018 22:35:18

We are talking here about Solid-State Drives, where a semiconductor chip holds the data that would normally go on a hard disk.
These chips can read data easily, but have a limited number of write cycles to any data block, so even changing 1 byte sometimes changes the whole file.
Software has to manage the files and directory structure so that critical disk blocks (like the root directory) don't wear out and render the whole drive inaccessible. This makes the location of critical files on the disk a lot more flexible than on a traditional hard disk.

I expect that there would be some hidden file on the disk which keep track of which blocks have been written to more than others, and which blocks have failed entirely.

Overwrite this information with random nonsense, and you may have halved the lifetime of your disk - or confused it entirely!
See: https://en.wikipedia.org/wiki/Solid-state_drive#Wear_leveling

Quote

I use Diskeeper that diverts a lot of of writes and reads to RAM and I have not noticed any deuteriation in my SSD,s as yet

RAM has effectively unlimited reads and writes, so this RAM cache should reduce load on your SSD, rather than increase it.