SSD vs SATA HDD

[TourGuide]

As I understand it, standard HDD drives when erasing a block of data simply remove the reference to that data block in the FAT. The data is actually still on the drive and can be found with the proper tools. Until it is overwritten (mulitple times usually) it continues to be available. This is where tools like Window Washer and other data erasing tools come in handy.

Here is my question - anyone know how SSD drives handle erasure of data they contain? Is it via this same method?

If it is, then using the old tools of overwriting the old data would be really hard on the new SSD drives. Seems in fact that wouuld be a really bad idea to use those tools.

 

[bigi]

Good question!
I'd say, it works in the sam way... even though I don't know for sure.
Erasing the data completely would take too much time, even with fast drives. Also, it would have to be determined what really full erase is.

 

[coxmaster]

Depends a lot on what you call "erased" IIRC you can recover data almost 100% of the time with enough patience and ability.

 

[frostedflakes]

Yeah I'm pretty sure SSDs function in the same way. The data itself isn't deleted, only the reference to it in the file table.

Something to keep in mind, though, is that wear leveling will move data around on the SSD, potentially overwriting the deleted files. Of course the safest way to ensure the data is gone would probably be to write zeros to the drive. Because it isn't magnetic like hard drives I'd assume multiple passes wouldn't be necessary, there shouldn't any residual data after a single pass. Also because of flash durability it'd be best to keep passes to a minimum.

That's just my assumption, though, maybe multiple passes are necessary. If you happen to find a good article or something on this please let us know, I'd be interested in reading up on it.

 

[TourGuide]

I *presume* that it works the same way too. Frosted, your point about wear leveling overwriting old data is well taken. I hadn't thought of that.

I've been curious about this ever since the benefits of SSD came around and prices started to come down from the heavens (still up there relatively).

After considering how the old data erasure tools worked it got me thinking and it also brought up the whole durability issue again - which ppl carp on about (the fanbois) but in fact IS an issue if data security and privacy are important. This is an important issue that I haven't heard much of anything about, but I'll keep looking for more information.