HELP! Disaster with 1TB Samsung 840 EVO and OWC Mercury Elite Pro Dual

Discussion in 'iMac' started by ggraves, Jun 29, 2014.

  1. ggraves macrumors newbie

    Jun 28, 2014
    Samsung has dropped the price of their 1 TB 840 EVOs to about $400 so I decided to try a couple to speed up my 27-inch Mid 2011 iMac. I ordered an OWC Mercury Elite Pro Dual to house the 2 SSD drives as RAID 0. The raid enclosure was to be attached via the Thunderbolt port on the iMac (at the hefty Thunderbolt premium price, I might add.) The iMac has two Thunderbolt ports, one of which is used for a Drobo array and the other is used for an old 30" cinema display.

    I have encountered nothing but disaster. I have removed the Drobo and have been trying to get the RAID array to work with the SSDs. The system freezes consistently just after boot on the TB port, but it partially works when attached via the USB 2 ports (the RAID device has a USB 3 port.)

    Does anyone have ANY experience with the OWC RAID enclosure and the Samsung 840 EVOs, or ANY Thunderbolt RAID enclosure with the 840 EVOs?

    These things aren't even heavy or large enough to make good doorstops, much less boat anchors.

    Thanks for any suggestions.

    George Graves
    Puzzled in PA
  2. aliensporebomb macrumors 68000


    Jun 19, 2005
    Minneapolis, MN, USA, Urth

    I own/owned the OWC Mercury Elite AL-Pro Firewire 800 version and the thing just was not reliable over time.

    Examples: Drives wouldn't mount at boot, drives would suddenly dismount in operation, or drives would take a long time to mount. I looked on the internet for reviews years after I bought it and some said the power supplies in these units were not really the greatest hence the erratic operation.

    Eventually the internal cooling fan stopped spinning and cooked the drives. I lost 3 TB right there about three weeks ago.

    I had called OWC prior to the fan incident about the issues with drive mounting and they claimed their dual bay enclosure was never meant to be used in the way I was using it - which is to say two separate volumes that formerly were in my PowerMac G5 being used as read/write drives).

    The manual that came with this device claimed you could use it that way. So their support line contradicts what the manual indicated.

    It sometimes would work, then sometimes wouldn't work. The fan issue was exacerbated by the fact that one of the two SATA cables was just long enough to prevent the fan from spinning if you weren't careful in putting the works together but this time the fan was the issue.

    I heard they make good stuff but I was not encouraged by the quality of this particular product.
  3. Fishrrman macrumors G5


    Feb 20, 2009
    My suggestion is to move to other hardware than OWC's...
  4. eduardrw macrumors 6502

    May 20, 2013
    The 840 EVO's are not designed to be RAID drives - they are consumer grade SSD's. Their firmware implementation is most probably incompatible with RAID configurations.
    The OWC enclosure has recommended/compatible HDD's. You will have similar problems with other enclosures - unless they slow down to "least common denominator" performance!
  5. Nuke61 macrumors 6502

    Jan 18, 2013
    Columbia, SC
    Per the Macsales website, the Elite Pro Dual has speeds "up to 389 MB/sec read" - my single drive 840 EVO in a Buffalo case has faster reads and writes than the OWC enclosure. My suggestion is to return/sell the OWC enclosure, or select the other setups (RAID 1, independent, etc.) and see if one of those choices work.
  6. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    Also ... checking the specs on the Elite Pro Dual specifies "hard disks" with no mention of SSDs, plus OWC doesn't offer any preconfigured SSD versions of this enclosure.

    The OP might have better luck with the OWC "ThunderBay IV", which is offered with, and specced for, SSD drives.

    *895MB/s achieved with 4 OWC SSDs running in a software performance RAID-0

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