koilada :
But this someone must be a pro, right? I guess not anybody can dig deeply.
Pro/Superman.
Even in Gutmann's original paper about it, data recover was only theoretically possible because there was a greater than 50% chance of determining the right value for the overwritten bit. Also consider that the original theory was for drive technology in the late 90s and pretty much everyone agrees (including Gutmann himself iirc) that with modern drives, there's no need to run tens of overwrites.
Still, peace of mind is nice and people are paranoid about things they don't understand.
koilada :
I 'll use that Eraser and hope its indeed simple. Thanks
Do such programs wear the discs?
The nice thing is that erasing a HDD is fairly easy, just time consuming if you want to run multiple passes. Really, at it's core, all any of these erase methods do is overwrite the entire disk with new data. The differences just lie in what kind of specific bit values they use.
That does mean you are writing an entire drive's worth of data every pass. So there is of course going to be some wear. With HDDs, the wear is probably not too much of a concern. For SSDs, where there is a somewhat hard limit in how much write and erase cycles the drive can take, this is more of a concern.