drive wipe - random or zeros

CCleaner for Windows
1

Qquestion:

What method does cleaner use to wipe disks?

I we that it is fast. .. having just used delete cmd line.

Reason I ask is not security Q...... it is about space & compression. With the win10 deadline approaching I am doing a lot of disk imaging at diff stages to backstop any probe (had a dual switchable gdfix laptop that caused headaches)...... and having a shock when a supposed empty disk is making v large images.

Zeroing the free space means MACRIUM GHOST ACRONIS etc just sees a large block of zeroes and squashes it to next to niL...... much quicker too.

So zeroes or random? Roadkill blanking util v slow. sdelete not too slow.

Any typos sort blame wretched tablet & predictive overrides.

2

Oops seems this damn tablet has let me put posting in wrong section.

Moderators plz rectify

3

Single pass is zeroes, and multi-passes end with a pass of zeroes, so effectively the same.

4

Ah sounds good just been getting sector copy images of same disk dropping from 150 to 200 gb down to 10gb, a 400gb drive down to about 8gb !! Used ccleaner on another machine about to prep so am happy don't need to lose a few hrs deleting it

Fab

5

Just saw it doing work on a machine upgdg.. see it makes crazy set of directories & subdirs named in iterations of zz. Then it mzkes one big file of random name and grows it. Good to know it is filling it with zeroes