Question about passing zeros to erase disk

[Jfallone]

While using disk utility, I interrupted the 7-pass feature at the fourth pass. Does this mean that 3 passes of zeroes have completed ENTIRELY and all that is required is a format? I'm a paranoid type and before I bring my machine back to the apple store as a trade in I want all of my stuff REALLY gone!

 

[saturnotaku]

Does this mean that 3 passes of zeroes have completed ENTIRELY and all that is required is a format?

Yes, though really one pass would have been sufficient. If the entire drive has been overwritten with zeroes, nothing is recoverable, at least with software. It's possible to get some of the data back, but to do such a thing requires highly specialized and extremely expensive equipment that tinkers with the physical drive itself. We're talking CIA-type stuff here, and nothing that Apple or the everyday person would have.

 

[Jfallone]

Thanks! That's what most of my research showed, however I had the time to run a 7 pass anyways and accidentally pulled the plug after four (battery is done). Was nervous nothing had been done even though common sense said three passes had been done. Thank you very much for your help!