Mid 2012 Macbook Pro Samsung Evo 850

Discussion in 'MacBook Pro' started by Ollie C, Aug 11, 2015.

  1. Ollie C macrumors newbie

    Jul 21, 2010
    Hi all,

    I've got a mid 2012 13" Macbook Pro. I've bought a Samsung 850 Evo 500gb from Amazon for it and am having a horrible time trying to get the thing to work.

    Initially I just installed the SSD in the HDD bay as you'd expect and attempted a clean install of Yosemite from USB. The install was excruciatingly slow - taking 3 hours to move from 13 minutes to 12 minutes with very little activity in the install log and very very rare signs of activity on the USB stick activity LED.

    I booted the original drive (10.10.2) via USB adapter and attempted to move files to and from the (freshly reformatted) SSD, I found that whilst the transferring of data itself was fast, it would pause and hang for moments whilst doing so, meaning a 200mb video file took close to 5 minutes in total to copy. Playback of the file from the SSD exhibited this same stop-start access.

    I next attempted to connect the SSD by the USB adapter. Yosemite installed quickly, booted and ran lightening fast. I put the SSD back into the internal bay and everything slowed right down; booting took an age then clicking anything when it'd booted caused it to beachball/hang. I have tried enabling TRIM, this has had no effect.

    I've seen similar cases all over the internet but nothing definitive towards actually fixing, a lot of dead ends. One other forum user mentioned a read/write error in a log referring to the drive as (Null). I noticed this briefly when attempting to install Yosemite, the installer said that I was unable to install to (Null) for a split second on the drive selection screen - this accompanied with a 30 second or so delay for Disk Utility to load (and really slow format time) says that my Macbook really isn't getting along with the drive.

    I did think that the SATA cable could have somehow damaged itself in the process (as it's common knowledge that they are more fragile than the Natural History Museum's collection of Victorian Butterfly pressings) BUT the original drive, back in the Macbook performs normally - definitely no weird hangs or delays in accessing or writing data. The SATA cable was replaced by Apple less than 6 months ago as well and has been absolutely fine since then.

    This whole thing is really frustrating. There are no firmware updates available for the SSD and as far as I can see, no firmware/EFI updates for the Macbook. I'm leaning more towards this being a problem with the Macbook as the SSD performs flawlessly with the USB SATA adapter. My next step could be testing it in my old blackbook although I don't have any installation media for that to hand.

    Any ideas anyone... please?!

    EDIT - I have also cleared NVRAM and verified the SSD (with no errors) in disk utility.
  2. snaky69 macrumors 603

    Mar 14, 2008
    I use a 840 in a 2012 15" with no issues. The 13's HD cable is known to be finicky.

    It's a cheap part and it's easy to replace, I'd give that a whirl.
  3. Ollie C thread starter macrumors newbie

    Jul 21, 2010
    There's warranty on the Apple repair I think so might book it in and get them to replace it. They'll probably try to sell me an Apple SSD first though.
  4. snaky69 macrumors 603

    Mar 14, 2008
    Seeing as they don't sell it outside of a BTO, I doubt they'll try and sell you one.
  5. Ollie C thread starter macrumors newbie

    Jul 21, 2010
    Just checked with my old drive... that's also SATA III running at 6 gigabit negotiated link speed so I'm less inclined to think cable now. Some people have suggested that a nackered cable might play up for a SATA III drive but not a SATA II drive but that throws that out of the window unless I'm being completely opaque about the matter.
  6. Ollie C thread starter macrumors newbie

    Jul 21, 2010
    thought they sold SSD upgrades?
  7. chrfr macrumors 604

    Jul 11, 2009
    The Genius Bar doesn't sell upgrades.
  8. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Based on your description, I too think it is the cable. That new SSD is moving a ton more data than the old drive, so it is to be expected the cable may show problems with the SSD and not the old drive. The fact that the SSD works fine in the external enclosure pretty much proves it is the cable.
  9. Ollie C thread starter macrumors newbie

    Jul 21, 2010
    Will try and get booked in and see if they'll do it for free; not a single available appointment in my region right now though. Especially annoying as it's a new cable... and the third one I've had.

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