See the following link - it applies to Crucial but other drives with garbage collection shouldn't be any different.
http://forum.crucial.com/t5/Solid-S...D-performance-why-is-it-important/ta-p/100276
Pure marketing nonsense from Crucial I am afraid. Let me explain in VERY simple terms.
When your OS updates or deletes a file, it updates the directory to say that the file is deleted. In the case of an update, it writes the new updated file somewhere else as well. The file is not in reality deleted - hence the various utilities you can get to recover deleted data.
But it does not tell the disk controller that the delete has happened. As far as the disk is concerned the deleted file is still valid and it cannot differentiate between the deleted file and current, valid files.
That is what the TRIM command is for. Its the OS telling the disk controller that file xyz is now deleted.
All SSDs have garbage collection. Crucial's marketing nonsense is just that, nonsense. They ALL have garbage collection. How they work various according the controller and how the manufacturer has implemented it. But in very simple terms all it does is tidies up data into nice neat blocks so that when you need to do a write, it can write to nice empty cells and can do so as fast as possible.
The problem is, when it is doing this "tidying up", unless the OS has told it what data is no longer valid (by issuing a TRIM command) it has no way of knowing, so it goes around reading and writing both good and bad data and consolidating all of it, including the bad data that has been deleted as far as the OS is concerned.
So what?
Well consider editing a 10MB PowerPoint presentation. All the time PowerPoint is doing background saves. Over a 2 hour period working on your presentation, PP will have saved the file 12 times, each time deleting the last save and saving a new copy. There will be 100MB+ of deleted data lying around and 10MB of valid data. The SSD will do its garbage collection on 110MB of data and use up 110MB of space when only 10MB should actually be used.
Now think of this happening all the time with your OS updating logs, temporary cache files, old documents etc etc etc. There is a HUGE amount of deleted data still sitting on your SSD and the SSD will busily go about its business tidying all of that up with loads of background reads and writes that need not be happening.
So what does this mean? It means that without TRIM, (a) your drive is much more full than it appears, and write times will slowly deteriorate as the drive struggles to find free space to write to. And (b) the drive will wear out much more quickly because it is doing much more writing than it should be doing. (It is also doing "wear levelling" to spread the writes out across the disk, but it is doing that with loads of bad data when it need not be doing so.)
Conclusion: You need TRIM for an SSD to work at its best. There is no escaping this fact. The SSD manufacturers are not all going to tell you this, especially if there is no TRIM support for their drive. But that's the fact. Garbage collection and TRIM are NOT the same thing and you need both for your drive to perform properly.
I was being kind to Crucial calling that link marketing nonsense. In fact it's just plain wrong. Sandforce - who make the controller Crucial are using - tell you that you need both TRIM and garbage collection and that GC alone is not sufficient.
