how can I increase endurance of X25-M by slightly lowering it's capacity?

[idata]

On another forum (http://c0t0d0s0.org/archives/5993-Somewhat-stable-Solid-State.html http://c0t0d0s0.org/archives/5993-Somewhat-stable-Solid-State.html) I've read this:

"Intel says that you can increase endurance of the X25-M by 3.5X by lowering its capacity slightly".

Anyone knows if it's really the case and how exactly it's done?

Thanks.

[idata]

Thanks!

[idata]

Thanks Redux, that explains why a full secure erase is required and why just reducing the partition is not enough.

Quite amazing how much endurance can be added by increasing the spare space.

[idata]

I should note that this method of increasing endurance is instead of TRIM. If you are using TRIM, the effect on endurance is the same as if you had reduced the capacity of your drive to be only whatever you actually have in use, so there is no point in the capacity reduction. i.e. using TRIM with 40GB free on the 74GB (sold as 80GB) drive gives you the same endurance as if you had reduced the capacity to 34GB without TRIM.

[idata]

^ what makes you say that?

[idata]

TRIM affects performance, not endurance. Before flash memory can be rewritten, it must be erased. Without TRIM, the contents of the flash memory are not erased when a file is deleted, it just marks that space as available. This is the same with hard disks as well, and the reason "undelete" apps work and why things like DBAN and Secure Erase are needed to actually remove data from an old drive. With TRIM, the SSD actually erases the flash when the delete command is issued. Without TRIM, the flash needs to be erased on the fly before being rewritten. TRIM moves the erase to the time of deletion to avoid unnecessary delays when rewriting that particular chunk of memory. "Garbage Collection" and manual "TRIM" commands do the same thing - explicitly erase chunks of memory that are marked in the filesystem as being available, so that they're immediately available for writing. TRIM doesn't even really do anything better, it just moves the actual erase function to the time of delete rather than at the time of rewriting data there.

Using a smaller partition increases endurance simply by having less data and more spare space. The larger spare "swap" space allows for less write amplification (how much extra data needs to be written to the flash chips in order to end up with your data properly saved). You have more working area, so you don't need to constantly rearrange everything to fit (which causes lots of extra writing to save a little data).

The Intel firmware will only use the space as spare if it's "clean". In theory, you should be able to shrink the partition then wipe the free space. However, I don't personally know of any utilities that do this (though I haven't really looked either). It should also be theoretically possible for Win7 to TRIM the free space after shrinking a partition, though I don't know if that actually happens. If you have an existing install on your SSD and another disk with some free space, you could always image the existing drive, do the Secure Erase, and restore the image to a smaller partition. This would result in the larger spare space without actually having to go through the install again.