SSD - Secure Erase or Quick Format

[Tedfoo25]

Hi there!

This is my first OS reinstall on an SSD. I am quite familiar with formatting HDDs, but have read that SSDs work a little differently. Essentially, I can either Secure Erase or Quick Format, if I have understood it correctly.

Some preliminary information:
The SSD is Sandisk Ultra Plus 256GB (which has no partitioning software of its own).
I have owned and regularly used the SSD for four months now, and it is half full (~120 GB used)
I want to do a fresh install since I am getting rid of 100GB of programs I no longer want, and also will be installing Windows 8.1 (upgrading from W8).
I have the Windows 8 disk.

Please could someone inform me which would be the best method to use in my case.

As far as I understand it, a Quick Format sends a voltage spike to every block which has been written to, effectively wiping the data on the drive; whereas a Secure Erase drains all the charge from every block on the drive, resetting the entire SSD to factory condition (though this has a small chance of bricking the drive). Since the drive isn't close to full, perhaps a Quick Format would be better?

Thanks!

 

[Kelthar]

From what I've been reading, Secure Erase works by either draining all cells or marking everything for delete and then sending a 100% TRIM command to the drive (effectively marking everything on it as garbage, which will then be erased).

The problem with quick formatting is that it does indeed mark things as garbage, but the way TRIM works on SSDs is by only TRIM'ing a sector once it's 100% garbage or only erase part of it once it's needed (that's why performance degrades if you have almost full capacity, because it has to TRIM before writing).

If you are installing Windows from scratch, whichever method you choose will have no difference. During reinstallation, if you wipe all partitions on the SSD and install Windows there, it'll issue a 100% TRIM command on its own.

I have found a few very informative answers on other forums, which I'll quote:

Erasing cells is done by fully DRAINING the charge from them.
And I am 100% sure it does in fact TRIM everything, this is why early on before OS TRIM was available people would secure erase their drives to restore new drive performance.
It might ALSO manually push for the immediate erasing of all cells and only inform you it is done after all cells have been erased... But that would be in addition to the TRIM not instead of and honestly its not actually necessary.

Unnecessary because the way TRIM works. TRIM informs the drive that sectors contain garbage data. Wear leveling algorithms can choose to read-modify-write on erase groups to clear up some garbage data (preferably a lot with minimal amount of data retained)... but choose the erase group with the most garbage and least useful data to ensure minimal write amplification. Typically though, the focus would be on erasing fully junk groups. If 100% of an erasable group (a group of 128 sectors, typically) is marked as garbage data then there is absolutely no reason at all to NOT immediately erase them. Thus if you TRIM 100% of the drive then you have started an unstoppable process wherein all the data on it is going to be permanently deleted by the GC as fast as it can as long as the drive has power. A process that takes mere minutes

In fact that is something that is bothering police forensics. A drive can be quick formatted (trim everything). they can disconnect it within seconds, but as soon as power is restored to it, it will begin systematically deleting everything and do so at a very rapid pace and cannot be stopped, recovered, or the data verified (to prove that the data is not planted, forensics only deal with disk images which are hashed and then compared to the hash of the original drive after the investigation)
http://www.jdfsl.org/subscriptions/JDFSL-V5N3-Bell.pdf

... there is still absolutely no reason to do it [secure formatting] when reinstalling windows (a simple quick format will get you identical results).. unless your controller encountered a bug that causes it to be unable to GC post full drive TRIM. In which case a secure erase might cause it to recover from that.

 

[RealBeast]

I would quick format.

Quick format simply erases the information file on the drive so it appears blank although all data is still there and could be recoverd and does not affect any other data blocks, a secure erase overwrites every data block. As long as you have had no issues with the drive a secure erase is not needed unless you are selling it to someone else and you want to delete all data.

Secure erase is also useful to return a drive to its new performance state when it has had lots of incompressible writes and poor TRIM.

 

[Tedfoo25]

I would quick format.

Quick format simply erases the information file on the drive so it appears blank although all data is still there and could be recoverd and does not affect any other data blocks, a secure erase overwrites every data block. As long as you have had no issues with the drive a secure erase is not needed unless you are selling it to someone else and you want to delete all data.

Secure erase is also useful to return a drive to its new performance state when it has had lots of incompressible writes and poor TRIM.

Thanks. So do you think that if I do a Secure Erase I will get very marginally better read/write performance than a Quick Format, or not?

 

[RealBeast]

No, not unless the drive has been used at a very full state for some time. I would just quick format in your case.

 

[Tedfoo25]

No, not unless the drive has been used at a very full state for some time. I would just quick format in your case.

It just occurred to me: won't a quick format have exactly the same effect as a secure erase because of TRIM? The remaining data from the old OS install will be marked as garbage and would be wiped within a few minutes, right?

 

[Kelthar]

I'll just quote myself, from my reply on this topic:

If you are installing Windows from scratch, whichever method you choose will have no difference. During reinstallation, if you wipe all partitions on the SSD and install Windows there, it'll issue a 100% TRIM command on its own.

 

[Tedfoo25]

I'll just quote myself, from my reply on this topic:

If you are installing Windows from scratch, whichever method you choose will have no difference. During reinstallation, if you wipe all partitions on the SSD and install Windows there, it'll issue a 100% TRIM command on its own.

Sorry, I glanced over it because it was a lot of text. Thanks very much though!

 

[RealBeast]

There is a significant difference between a secure erase and a quick format, an SE is not just a TRIM on all cells -- it is a hardware level "flush" of all stored electrons that resets the device to its original state.

Nonetheless, you do not need to do an SE.