SSDs with "onboard" TRIM

Discussion in 'MacBook Pro' started by mcmul, Dec 14, 2013.

  1. mcmul macrumors 6502

    Dec 14, 2009
    Can anyone recommend an SSD with onboard TRIM and an excellent reputation?

    I have the Samsung 840 SSD in my MBP however it is slightly too small. I am looking to upgrade the 256 GB capacity to either 512GB or 768GB. However this time around I would an SSD with onboard TRIM as I do not use the "TRIM Enabler" software that seems so popular around here. Though I have not seen any performance degradation, I want the peace of mind this time around. Though it isn't relevant, I will be moving the 840 into my MicroServer to give that a good kick :D
  2. dusk007 macrumors 68040


    Dec 5, 2009
    There exists no such thing as onboard Trim.
    Every SSD has garbage collection. GC only works maximally efficiently if Trim is enabled and it has knowledge about valid and non valid data. Without Trim you eventually have an essentially 100% full SSD. That can still work okay (if there is enough spare area) but GC has to work much harder, which leads to higher write amplification, which means NAND endurance is much more stressed.

    There is no such thing as onboard Trim. There never was. Most SSDs released lately have a rather small spare area for more efficient space use, which isn't a problem with Trim enabled but it really should be enabled. Old Sandforce SSD had 27% spare today they are at 7% or less and non sanforce are usually very low with sometimes virtually no spare at all.
    If you don't use Trim leave some space (10% at least) unpartitioned.

    Trimenabler just does for any SSD what Apple only does for its own SSDs. You won't get an Apple SSD afaik so just use Trim Enabler.
  3. mcmul thread starter macrumors 6502

    Dec 14, 2009
    Ah, well. Thanks for that information and setting my facts straight; I had absolutely no idea. I remember reading something that referred to "onboard" TRIM in the past and so I must have either misread or they were misinformed as well. Really appreciate that. Cheers :cool:
  4. priitv8 macrumors 68040

    Jan 13, 2011
    You can think of it as follows: Apple's SSD driver does not use TRIM command on any other SSD than their own. What TRIM enabler does, is just override the drive identification code in said driver, so it will validate all drives as Apple's.
    In more detail, there is a string
    in the driver code that simply gets overwritten with zeroes.
    All Apple SSDs have this APPLE SSD as part of their name in identification string:
    Apparently the hack simply makes any drive name match so TRIM gets used on the drive.
  5. undesign macrumors regular

    Nov 4, 2013
    Its amazing how Apple won't implement TRIM into Mac OS except for its own SSD drives.
  6. MatthewAMEL macrumors 6502


    Oct 23, 2007
    Orlando, FL
    It helped me to think of it this way:

    TRIM is a Operating System command that is issued to the device telling it a file/folder/etc has been deleted.

    Garbage Collection is a Firmware Level feature that actually does the 'deletion' of the file/folder/etc on the SSD. (it's not really a deletion, but for simplicity's sake, we'll call it that)

    For most efficient (speed/longevity) use, TRIM + GC is required.

    Yes, OWC...even you need TRIM.

    I would highly recommend the Samsung 840 EVO line. They have a 2.5" SSD and a mSATA SSD (up to 1TB) for guys like me with a mSATA slot.

    Thank you, Alienware. I can carry around a 2x1TB SSD RAID0 in my laptop. Sweet.
  7. dusk007 macrumors 68040


    Dec 5, 2009
    Basically GC is the same thing defragmenting was for HDDs. It consolidates empty space for better write performance, because SSDs never overwrite the old data but just write updates elsewhere and delete the old stuff whenever they have time to. GC has no clue about what a file/a folder or anything is or whether it is deleted. It knows LBAs and when one is overwritten (new data) it knows it can delete the old data.
    I think they had just some bugs with early firmware versions relating to Trim on some SSDs. Because they didn't want to deal with the support questions they just disabled Trim. They simply never revisited that decision. Windows/Linux enable Trim everywhere and expect the SSD manufacturers to fix the firmware. I assume there also was some bug in Apple's Trim implementation and they didn't figure it out so they just went the save route.
    Today it is kind of a bad joke. As we know Apple they always like it when there own stuff behaves better. Safari can do flash on the iGPU, Chrome cannot. VLC took forever to work on the iGPU. This SSD Trim business is just another example, where Apple doesn't seem particularly interested in having 3rd party stuff be too appealing.
  8. maflynn Moderator


    Staff Member

    May 3, 2009
    Agreed, but you know what, it affected my purchase decision be getting an apple SSD. I opted for a rMBP over the classic for the screen, but the apple SSD was part of my decision matrix.
  9. littlepud macrumors regular


    Sep 16, 2012
    I doubt Apple will revisit TRIM for 3rd party drives. Most recent Apple machines don't have (officially) user-serviceable drives anyway so the point is probably moot.

Share This Page