Replacing a SSD to protect my data?

stanw

macrumors 6502a
Original poster
Aug 29, 2007
841
5
I have a new 27-inch iMac with a 500GB SSD. I understand that there is no way to securely wipe a SSD, so this has me wondering:

1. Can I overwrite all the data on my SSD by formatting it and just transferring over 500GB of new info to it, or will this still not work?

2. How difficult is it to just buy a new SSD and swap out the old one when its time to get rid of my iMac?

Thanks!
 

macthefork

macrumors 6502
Feb 2, 2013
467
7
1. No, there are likely many blocks that are not accessible to the OS that the SSD controller uses for wear leveling. If data is written to these areas, deleting or overwriting the disk will not remove them.

The best thing to do is use disk encryption when new. This will prevent access to an data on the disk (without the password)

2. Swapping out the SSD can be done. However, it's a delicate operation and can easily result in damage. Easier to simply encrypt the disk and reformat it when you're done with it.
 

stanw

macrumors 6502a
Original poster
Aug 29, 2007
841
5
1. By "disk encryption" do you mean to use something built into OSX or some 3rd party application?

2. I have been using it over the past few weeks, so I'm thinking at some point I'm going to need to swap out the drive. What damage can easily result from swapping out the drive?

3. If I do encrypt the disk, by reformatting it when I sell it, it will not remove the encrypted disk, it will just be hidden, though it will still be encrypted so even if someone recovered it they would not be able to access the files, is this what you mean?

Thanks!
 

yjchua95

macrumors 604
Apr 23, 2011
6,725
230
GVA, KUL, MEL (current), ZQN
1. By "disk encryption" do you mean to use something built into OSX or some 3rd party application?

2. I have been using it over the past few weeks, so I'm thinking at some point I'm going to need to swap out the drive. What damage can easily result from swapping out the drive?

3. If I do encrypt the disk, by reformatting it when I sell it, it will not remove the encrypted disk, it will just be hidden, though it will still be encrypted so even if someone recovered it they would not be able to access the files, is this what you mean?

Thanks!
It's built into OS X in the form of FileVault 2. You have to enable it manually.

For late-2013 iMacs, there are no third party replacement SSDs.
 

stanw

macrumors 6502a
Original poster
Aug 29, 2007
841
5
Are there no 3rd party replacement SSDs because they are not released yet or because of some other technical barrier or reason that will not allow them to be swapped out?

Thanks.
 

p3ntyne

macrumors 6502
Jan 10, 2014
406
3
Sydney, Australia
Are there no 3rd party replacement SSDs because they are not released yet or because of some other technical barrier or reason that will not allow them to be swapped out?

Thanks.
They have not been released due to Apple's use of a new interface. They can easily be swapped.

Also, keep your eyes on OWC - they are likely to release one this year.
 

yjchua95

macrumors 604
Apr 23, 2011
6,725
230
GVA, KUL, MEL (current), ZQN
Are there no 3rd party replacement SSDs because they are not released yet or because of some other technical barrier or reason that will not allow them to be swapped out?

Thanks.
The reason is that Apple switched to a new interface between 2012 and 2013 ones. The 2012 blade is mSATA, while the 2013 blade is PCIe.

OWC only has replacement SSDs for the 2012 ones. However, they may be releasing a PCIe variant this year.
 

Chippy99

macrumors 6502a
Apr 28, 2012
973
27
Stan, you can securely wipe an SSD. Sorry I go on a bit below, but please read, if you are interested.

You need to issue a ATA Secure Erase command to the SSD, which will wipe it completely and incidentally it returns it to a factory fresh condition and restores the performance to the level of a brand new SSD. (Even with Trim enabled, the performance of SSD's does slowly decline as they are used more and more and fill up more.)

To be clear, this does NOT just fill all the cells with zeros (with the inherent risk of data being hidden in spare blocks somewhere that you cannot get at). When you invoke a ATA Secure Erase command, the SSD controller applies a voltage spike to all of the cells simultaneously, flushing the stored electrons from the flash memory cells. It takes only a minute or two and it's done.

Issuing a ATA Secure Erase command on a Mac is easier said than done however! You need to boot a Linux image with the appropriate tools installed, and do it from there. Luckily there is such an image, that will boot your Mac and it can be found here:

http://partedmagic.com

It used to be free, but sadly they have started charging $5 for it now, but still not bad.

What you need to do is described here:

http://www.overclock.net/t/1227597/how-to-secure-erase-your-solid-state-drive-ssd-with-parted-magic

I have tested this, and confirm that it is easy and straightforward to do and it works. (When I did it first, the hardest thing was getting a linux USB stick to boot on an iMac, but they seem to have cracked that so it's now a doddle.)

Your SSD will be COMPLETELY blank and returned to factory-fresh condition. There are no recovery tools known to man that can retrieve any data from it once this is done. (OK, so maybe the CIA could conceivably get some scraps off it, but even then I think not. Unlike a hard disk where residual magnetic traces may be present, the SSD is completely wiped and you could hand it over to anyone you like with no fear of them reading anything.)

Hope this helps?
 
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