Apple SSD + TRIM + Full HD Encryption

[Avery1]

Considering a new MBP with the Apple SSD + Trim, where i would use FileVault initially, and eventually Lion FileVault for full-disk encryption.

- Does TRIM cause files to be unrecoverable when deleted from an SSD via 'normal' delete means?
- Will the use of full HD encryption (i.e. Lion) significantly affect SSD performance?
- Will the use of SL FileVault significantly affect SSD performance?
- Does this change is using a 3rd party SSD without support for TRIM?

 

[SavMBP15]

Considering a new MBP with the Apple SSD + Trim, where i would use FileVault initially, and eventually Lion FileVault for full-disk encryption.

- Does TRIM cause files to be unrecoverable when deleted from an SSD via 'normal' delete means?
- Will the use of full HD encryption (i.e. Lion) significantly affect SSD performance?
- Will the use of SL FileVault significantly affect SSD performance?
- Does this change is using a 3rd party SSD without support for TRIM?

For what its worth I use CheckPoint Full Disk encryption on my Mac (required for my job) and I notice no impact to my day to day activities. Its all on the fly.

 

[Avery1]

For what its worth I use CheckPoint Full Disk encryption on my Mac (required for my job) and I notice no impact to my day to day activities. Its all on the fly.

That's good to know, as I may need to use a full disk encryption option until Lion.

Curious... are you using an SSD with it?

Any other thoughts?

 

[Tonepoet]

TRIM by itself doesn't actually delete the data. That'd be a waste of writes. It just tells the controller that blocks which have data on them are writable based on file system data. You're probably going to want to back up your system, do an ATA secure erase on the drive somehow, do a clean installation of the operating system and turn on file encryption first thing so the data's scrambled as soon as it's written down in the NAND. Otherwise whatever data you have on it currently is probably going to be recoverable since you can't know when/if it's being overwritten, even through features like Secure Erase, because the OS and SSD pointers are still different. By the way, how does the Apple SSD know it's trim enabled again? Hope it's in the firmware, rather than anything that's rewritable.

 

[Avery1]

TRIM by itself doesn't actually delete the data. That'd be a waste of writes. It just tells the controller that blocks which have data on them are writable based on file system data. You're probably going to want to back up your system, do an ATA secure erase on the drive somehow, do a clean installation of the operating system and turn on file encryption first thing so the data's scrambled as soon as it's written down in the NAND. Otherwise whatever data you have on it currently is probably going to be recoverable since you can't know when/if it's being overwritten, even through features like Secure Erase, because the OS and SSD pointers are still different. By the way, how does the Apple SSD know it's trim enabled again? Hope it's in the firmware, rather than anything that's rewritable.

Thank you for the useful information... I was curious if trim was just an indicator allowing over-write. I'm not quite following re: trim being enabled at the firmware level. With the Apple BTO SSDs I assume if you enable TRIM within SL, this is a software level feature.

I'm not completely clear on the technical workings of SSDs and how the over provisioning works. Because of this, do partial encryptions (such as using an encrypted sparse file image) or full-hd encryption have the potential to store unencrypted data on the SSD?

 

[Avery1]

This article will be useful to those asking these same questions:
http://www.anandtech.com/show/4485/back-to-the-mac-os-x-107-lion-review/18