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macrumors 6502a
Original poster
Jan 22, 2014
So what options do we really have to protect ourselves when we plan to sell our old rMBP's that have the new flash storage/SSD?

Apple makes the security options "greyed out" in disk utility so you can't readily do a 7-pass secure erase any longer. I know there's a work around by formatting the drive and making it encrypted, which then allows for the normal security options. However, how much damage are we really doing to the flash storage with a 7-pass secure wipe.

Is this a case of taking a chance your personal information will be stolen, or severely damaging the life of the drive? I saw a thread on here posted where a guy was worried about even doing a simple disk erase in disk utility simply because he believes the drive performance will suffer.

Your thoughts?


macrumors 6502a
Oct 27, 2006
New York City
Wiping a SSD is not like doing it to a HDD. In fact it doesn't really matter how many passes you do on a SSD, it never really gets wiped.

I am at loss myself when it comes to reselling. It still would take equipment most people don't possess to lift and reconstruct your data but still...

Must turn ON FileVault when you boot it for the first time.


macrumors 68040
Dec 5, 2009
A 7-pass would be completely idiotic on an SSD. It is on modern HDDs too which are unrecoverable after a single cycle. It was theoretical possibility on old HDD with much bigger bits but today a single earse is all you need.
Since NAND works differently you'd just need one and there is not even a theoretical chance for recovery. But you need to write over everything because you cannot secure erase single files.

On an HDD if you just format you can recover files via special software. On an SSD you cannot after a single Trim. The only way is unsoldering the NAND and attaching them to some special controller that reads out all that is left and somehow makes sense of it, which is can be quite tricky depending on how many random writes occured. No normal person can do that.

Just for selling trimming the disk is all you need to do. If you want to be safe from the NSA. Fill the drive with garbage and delete everything. Fill the last 10% a couple times to write over the spare area if your SSD has any significant amount of it.


macrumors G3
Jul 24, 2009
You don't need to wipe an ssd. If you were to repartition it the data would be unobtainable to most people. To get at it you would have to physically dismantle the drive as in remove the chips and read them.


macrumors Haswell
May 3, 2009
S. However, how much damage are we really doing to the flash storage with a 7-pass secure wipe.

Due to the physics of SSDs as opposed to magnetic drives, you don't need to do a 7 pass secure wipe, once the information is deleted out of SSD, its gone forever and doing a 7 pass wipe will definitely shorten the life span of the drive.
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