Momentus XT & FileVault 2

Discussion in 'Mac Accessories' started by Eradik, Jul 31, 2011.

  1. Eradik macrumors regular

    Jul 10, 2011
    Pacific Northwest
    So, since I'm a new owner of a Momentus XT I was wondering if anyone had any insight on FileVault 2 on Lion. Will doing a full disc encryption with FV2 cause any negative performance with my XT? I know that just by design FV2 will cause disc slowdown, but will it cause any issues, specificially, with the 4GB SSD portion of the drive?

    Since everything is encrypted, does it make it so the XT won't be able to tell what I use most often to properly cache it? Or will it still store the encrypted file so that when it's unencrypted it will still be on the SSD portion?

    Anyone have any insight before I activate this?

  2. Objectivist-C macrumors 6502

    Jul 1, 2006
    It won't have any unusual effects. The XT's caching mechanism is block-level, so it's agnostic to things like partitioning, file systems, or encryption.
  3. Eradik thread starter macrumors regular

    Jul 10, 2011
    Pacific Northwest
    Exactly what I was hoping to hear! Thank you very much!
  4. jpalten macrumors newbie

    Dec 16, 2010
    Interesting, I mailed with Seagate and they told me caching happens at file level. This sounds a little funny, since that would mean the disk needs to know about file formats (FAT, NTFS, MacOS journaled, etc). Block level or sector level caching sounds much more logical.

    Has anybody actually got this running?
  5. simon57 macrumors newbie

    May 24, 2012
    Hi I have the exactly same question. I recently upgraded to Momentus XT with FileVault2 from another 7,200rmp drive but I hardly see any improvements in performance. I was going to remove encryption from Momentus drive and see if things get faster. I was wondering if you have have already tried this and if this improves anything.
  6. iynque macrumors newbie

    Nov 6, 2006
    I installed a Momentus XT (ST95005620AS) in my MacBook Pro. The boost in performance was small, but obvious and noticeable. Of course, I was upgrading from a 4200 RPM drive to a 7200 RPM SSD hybrid drive, so that is to be expected.

    After using it for a while (a year or so) I decided to enable FileVault 2 encryption under Lion. I haven't had any problems whatsoever. I also haven't noticed any performance hit from having encryption on. It may be slight, but if it's there it isn't noticeable.

    So, even without FileVault, there isn't much of a performance boost from having the hybrid drive. It's a boost, but it's no true SSD drive. I think though, since I didn't see a performance hit after turning FileVault on, the hybrid functionality must still work under FileVault.
  7. mabaker macrumors 65816


    Jan 19, 2008
    That's very helpful, actually.

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