Should I Enable TRIM with 256GB Samsung 470 SSD?

Discussion in 'MacBook Pro' started by harryhood, Sep 19, 2011.

  1. harryhood macrumors regular

    Joined:
    Mar 15, 2006
    #1
    I've just installed a 256GB Samsung 470 SSD in my 13" 2.7ghz MBP. I also have an optibay with the original HDD installed.

    I never setup TRIM. I just installed the SSD and installed Lion. (all my software is all installed, its full set)

    Do I need to install TRIM using this version and these instructions: http://digitaldj.net/2011/07/21/trim-enabler-for-lion/

    Help is appreciated, don't want to run into any problems.
     
  2. SolidSteel144 macrumors newbie

    Joined:
    May 3, 2010
    #2
    The SSD should have decent garbage collection.
    If you download and delete large files often, you might want to enable it.
     
  3. spencers macrumors 68020

    spencers

    Joined:
    Sep 20, 2004
    #3
    I enabled trim using the instructions in that link with my 256gb Samsung 470. Works fine.

    If you're wary about doing it, make sure to have a Time Machine backup, just in case.
    *Then again, you should already be backing up* :)
     
  4. harryhood thread starter macrumors regular

    Joined:
    Mar 15, 2006
    #4
    So one says I don't need to, the other says I do.

    *mind blown*
     
  5. yui4 macrumors 6502

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    May 26, 2011
    #5
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    I enabled it. There's been no performance issues and it has given me peace of mind. I've had enabled for 2 weeks with no problems
     
  6. maflynn Moderator

    maflynn

    Staff Member

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    Location:
    Boston
    #6
    I guess is all depends. If the samsung drive uses a sandforce controller then you may be better off not enabling.
     
  7. yui4 macrumors 6502

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    #7
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    I don't think the Sam 470 has a sandforce controller
     
  8. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #8
    Okay, here's the deal. Nobody really knows and we are all guessing, hence the conflicting answers.

    The Samsung 470 SSD, as well as all newer SSDs, has garbage collection built into the drive's firmware and is designed to keep the drive performance up even without TRIM from the OS. Now whether or not this firmware based garbage collection will keep the drive performing like new when it is two years old, nobody knows.

    Remember, even with no TRIM the worst that can happen is your write speeds only might get slower, read speeds will be the same. Your drive will not be damaged in any way by not using TRIM, it just might have slower write speeds after you have written to every single NAND cell on the SSD at least one time. That might take a long time. And this is assuming the firmware garbage collection is ineffective also.

    So do you want to run a kext hack that is at the core of the OS so you can have TRIM? I am concerned about data loss/corruption from a hacked system file like this. I do realize the hack thread is full of users who report no problems, but it still scares me.

    With all of this in mind, here is what I am doing and would suggest to users. While your SSD is still fairly new, run a disk speed test several times in a row and note the average speeds and write them down. Run the same speed test again every few months and watch for a large drop in write speeds. If you ever do see a drop in write speeds, that is a sign the drive needs to be TRIM'd. Then you can enable TRIM using the terminal commands you linked and afterward boot into single user mode and enter the command "fsck -ffy" (without the quotes). You need Lion to do this. The fsck command in Lion will TRIM all free space on the SSD and restore like new write speeds.

    After you have run fsck to TRIM, you can turn the hack off and restore the default kext file using the terminal commands you linked.

    You can go through this procedure any time you see a big drop in write speeds. This will keep your SSD performing like new without the risk of running a hacked system file all the time.

    As I mentioned, you may find the firmware garbage collection is sufficient and never notice any write speed drops. We just have to wait and see.
     
  9. harryhood thread starter macrumors regular

    Joined:
    Mar 15, 2006
    #9
    Thank you for taking the time to explain that!
     

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