Failure to do so will put a tremendous (and I cannot stress this enough - TREMENDOUS) amount of stress on NAND flash. If you want to just keep it simple, the answer is: on Windows 7, you ABSOLUTELY need to disable the built-in scheduled defragmentation on any filesystem/volume that is on a physical SSD. If you have a system with mixed drive types, e.g SSD for C: and MHDD for D:, you'd just need to disable it for C.

It never ceases to amaze me that vendors never document this behaviour. I can explain the further details of how DATA SET MANAGEMENT (TRIM) works at the ATA level, but I think ultimately what you're wanting to know is something Microsoft needs to answer (with regards to what I/O operations trigger DSM/TRIM), and/or Intel needs to answer (if you're using their AHCI drivers (you didn't provide a screenshot of the Drivers tab - the Details tab doesn't help here)), since Intel is the one who actually implements the layer that decides when to issue DSM commands to the drive. e-works/ - please see the question 'So what about OSes that support TRIM natively? How does that work? Do I need the Optimizer?' (this subject is not specific to the Intel Optimizer).In the meantime, I've partially blogged about this question already: » /201 I won't be able to get to responding to this til maybe next week.

Windows defrag ssd