5 Replies Latest reply on Feb 12, 2010 8:36 PM by ambizytl

    Definitive advice on whether to defrag or not, and if so how, please


      I have an Intel x25m 160Gb (G2) SSD.  I am using Windows 7 64 bit.  I'm confused about the need to run "defrag" programs or not.


      My understanding is that with Windows 7 and having a G2 SSD, TRIM is enabled automatically and this will do whatever housekeeping to my SSD that is necessary.  Is this correct, please?


      Diskeeper has "Hyperfast" for SSDs and Perfectdisk has the "consolidate free space" command.  Will either of these damage my SSD if I run them?  Can I run them (either of them) at the same time as having TRIM enabled?  Will my SSD benefit from either of them being run in addition to the TRIM feature?


      What I have read on the web suggests that neither of these third party programs are necessary but this is not what is said on the Diskeeper and Perfectdisk websites.


      Grateful for some advice, please.  I have x2 HDDs for data and I will run defrag on them in the normal way.



        • 1. Re: Definitive advice on whether to defrag or not, and if so how, please

          not an expert... but this my understanding


          You don't need to defrag an SSD.


          With mechanical hard drives, data resides in only one place. Where the operating system thinks data resides, it actually does. This is why conventional defrag programs work.


          With SSDs, the SSD spreads data out via its own in order to distribute the wear on the flash cells. so whilst the operating system thinks data is nice and packed together neatly (or perhaps it thinks it is defragmented), in reality the SSD will be employing wear leveling and spreading the data out anyway. Because the access times are so low on SSDs, it is my understanding you cannot physically tell the difference when the drive reads memory from cells that are spread all out over the drive. All that happens when you defrag the SSD, is data will be redistributed even more.


          That's my basic understanding, which I have probably done a horrible job of converting into words... but in essence, you don't gain anything (except wear..!) by defragmenting the SSD.



          Yes, windows 7 with the default AHCI driver (not sure about plain IDE driver..) with a G2 drive, with the relevant firmware, will keep the drive up to spec.


          I don't believe you will see any benefit if you run either of those utilities on SSDs. They are for mechanical drives with horrendous access times.


          Also, it may pay to check that Windows has detected your SSD properly... if you check the schedule for Windows 7 defragmenter, you should see if you click "Configure Schedule" and then "Select Disks" and you should see that the SSD is no where to be found here. (it will be listed in the main defragmentation window, however). This is moot if you have disabled the inbuilt defrag, however.

          • 2. Re: Definitive advice on whether to defrag or not, and if so how, please

            Thanks very much for your advice.  It is very clear.  The only thing I notice is that Diskeeper's Hyperfast is specifically for SSDs (?perhaps G1 models?) and Perfectdisk say that running their consolidate fee space routine triggers TRIM.  So this is still a bit confusing - not your advice - theirs!.  Are they talking about non-Trimable situations using either an earlier OS or an earlier (G1) SSD?


            My SSD is indeed missing from the Select Disks list.  I think I'll run the W7 defragger (or one of the others) just enabling it for my HHD mechanical disks.  The Intel manual for the SSD says it doesn't need to be defragged.  Perhaps Diskeeper and Perfectdisk need to update their advice as more and more people will adopt SSDs as their price comes down.

            • 3. Re: Definitive advice on whether to defrag or not, and if so how, please

              I think you are correct in that it would be applicable to certain SSDs, and possibly like you suggested, non-TRIM capable configurations.


              Here is an applicable post on the subject, from someone at DiskKeeper directly: http://communities.intel.com/message/59478

              • 4. Re: Definitive advice on whether to defrag or not, and if so how, please

                Thanks.  Seems like there is no point in using a third party (or Windows) defragger on G2, Trimmed drives.