I recently acquired a Momentus XT hybrid hard drive. This is a traditional spinning HDD with a small SSD portion for frequently used files.

I know that normally you are not supposed to defrag SSDs, as it does not help performance and can significantly reduce the life of the drive. But you do need to defrag an HDD to keep good performance. So where does that leave us for hybrid drives? Do I need to turn off defragging in Windows to preserve the SSD portion? Is the on-disk controller smart enough to handle defragging correctly? Is there some utility I need to set it up that I missed?

Additionally, for SSDs you normally want to check for and enable TRIM support... but this makes no sense for a HDDs. Where does that leave us for hybrid drives? Should I try to enable TRIM or not?


From Seagates's FAQ:

Turn off Windows automatic defrag.
Like SSDs, Momentus XT works best without frequent defrag.

Mine (a laptop), runs 24/7, I do a bi-weekly defrag of the HDD. As far as I know, there is nothing we can do about the SSD. I have not found any evidence to the contrary that defragging the HDD has been detrimental. My boot times over the past year have stayed consistent at 31 seconds (this includes doing the bi-weekly defrag for those 12 months, on a bi-weekly basis). I have not found any info that states anything about TRIM or looking after the SSD. I use Mechanic Pro 10 for maintenance,and it always shows 'NO SSD' drive found. Sooo... I take that to be a good thing. I have updated my Mechanic Pro to 11.1 and still, 'NO SSD' Found.

That has been my experience for the last year.

Update: This is what I found on the Seagate message board:

The Momentus XT Adaptive Memory algorithm is an LBA-based algorithm that looks for small portions of data that take the drive a disproportionate amount of time to access. It then puts these portions of data in the Solid State storage for quicker access. A disk defragmentation operation in some cases will move these small portions of data and as such invalidate the need for having the previously associated LBAs in Solid State storage. However, Seagate's analysis has shown that many of these data portions are not moved with a disk defragmention because, while small, they are entire 'files' which the defragmentation cannot determine a need to move.
With this understanding Seagate recommends that a user should run disk defragmentation on a Momentus XT for the following reasons:

  • Disk defragmentation will be beneficial for data that remains on the disk.
  • The majority of the data that was in the Solid State storage prior to the defragmentation will still benefit from being in the Solid State storage after defragmentation.
  • In the case where the data that was in the Solid State storage no longer benefits from that location the Adaptive Memory algorithm will appropriately remove it and free the space up for more pertinent data.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.