Intel X25-M G1 (no TRIM) SSD - format and restore just as good as TRIM?
I looked into this again (six months after my original post) and had much better luck: I found the ATA Secure Erase wiki entry. It shows you how to use hdparm to tell the SSD to do a "Secure Erase". From the article:
When a Secure Erase is issued against a SSD drive all its cells will be marked as empty, restoring it to factory default write performance.
The exact steps I took were:
- Imaged my entire drive (I used an old version of Acronis True Image, but any imaging utility should work fine),
- Connected the drive to the SATA controller on my linux box (hdparm needs to be connected to a drive controller - USB adapters won't work, I believe basically all "adapters" will not work with hdparm),
- Followed the instructions on the above wiki - and you should read the wiki carefully before you attempt this. On the off chance that the link breaks someday, the short summary is (where X = your drive, i.e. "sda"):
- hdparm -I /dev/X (look at the parameters for your drive, and make sure it is the CORRECT drive! Also make sure it says "not frozen" under security.)
- hdparm --user-master u --security-set-pass dummypassword /dev/X (you need to enable security/password protection to be able to send such a devastating command - the password and security will be cleared automatically after the drive is wiped) (and you can use any password you like)
- hdparm --user-master u --security-erase dummypassword /dev/X (Secure Erase the drive) (Again, please read the original wiki - these shortcuts are just a "backup" in case something happens to the original article.)
- Copied the image back on to the SSD
- Voila! SSD is behaving as if it was just off the shelf.
I didn't do any before/after measurements, but several people have and it sure looks like the drive is performing like new.
There's also an option to do it using an MS-DOS-only HDDERASE.EXE from 5 years ago - I spent a little time with it and think hdparms is a far superior option. There are a lot of forum postings and blogs about this out there now - google around until you feel comfortable.
But not too comfortable - you don't want to wipe the wrong disk or find out your image was corrupt!
Hmm, sounds risky, per Ars:
Neither is there a clear route to resetting the remap table. Intel told PCPerspective it was working on a good solution, but that one isn't available yet. PCPerspective tried several interim solutions, including using HDTach to rewrite every sector on the drive many times, which, over time, simplified the remap table. The process, though, requires a complete wipe of the drive, lots of time and effort, and lots of writing, which reduces the drive's lifespan. Moreover, once the remap table reached a certain level of fragmentation, this technique didn't prompt the drive to adapt, but rather it worsened the problem, pushing reads to less than 10MBps after many runs.
A more complete system involves using low-level IDE commands to completely shred every sector of the drive, including the remap table, and reformat, restoring the drive to a virgin state. However, this is difficult; it requires turning off AHCI, booting in DOS, and using an obsolete, no longer available older version of an obscure drive-wiping tool. Once this is done, the mere act of imaging an operating system partition back onto the drive restores much of the fragmentation.
Intel was supposed to release tools / utilities for this; Have you tried looking at the Intel Solid State Drive Toolbox?
http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18455