About to sell my 2013 rMac. Is 3 pass zero enough? I plan on selling my late 2013 rMBP  soon. I was wondering what your opinions are on me using a 3 pass zero on a SSD? Is it enough? I do have some sensitive data on there (bank info, passwords to important things at work, etc.). I also don't want to damage the SSD because I hear these passes can hurt the hard drive. Apple said that I don't even need to do that because SSD are just that great. Is that true? 

Thank you.
I believe Apple's position is a standard erase is good enough on SSD. In the article on secure erasing, they recommend enabling FileVault before you ever introduce any sensitive data to the drive so that you can just throw away the encryption key and not need any passes of erase to be secure.


http://support.apple.com/en-us/HT201949


That being said, in your situation, I wouldn't do a 3 pass erase on an SSD and I also wouldn't do a simple erase with no passes. 

Instead, I'd turn on FileVault 2 (Assuming you have a newer OS) and then boot to recovery mode and repartition the drive. Be sure to not unlock the drive but simply repartition it to an empty HFS+ partition, no passes needed.

That ensures that each writable block is totally encrypted and randomized so that it's impossible to tell what was free space and what was files, let alone do data recovery.

The passes are a marginal hit on the drive's life (they are rated for hundreds to thousands of passes), but one complete wipe might be as much wear as three months of heavy use. What makes the passes worthless is they waste your time and are un-necessary additional wear on a consumable part (the SSD).