Problem with OWC Mercury Accelsior_E2

Discussion in 'Mac Pro' started by iPadPublisher, Jul 16, 2013.

  1. iPadPublisher macrumors 6502

    Apr 14, 2010
    I posted previously about how I'm keeping the current Mac Pro, and simply maxing out where I can to make it for another year or so... I ordered the OWC Mercury Accelsior_E2 960GB unit, cloned my OWC SSD drive, and booted it up. Imagine my shock as my boot time from 0 to deskptop went from 49.8 seconds (average of 3 boot ups) to 1:07.7 -- nearly 20 seconds LONGER than with the SSD drive. I'm shocked!

    Anyone have any ideas on what may be going on here? I haven't called OWC yet, on the hopes that this is something silly that I've overlooked, but for the price I'm obviously not very happy at the moment. I was expecting a moderate DECREASE in the boot time as my first indicator of good things to come. Sigh.
  2. comatory macrumors 6502a


    Apr 10, 2012
    im no expert but i would try resetting PRAM first. also try different PCI slot.
  3. 666sheep macrumors 68040


    Dec 7, 2009
    Reset PRAM as said above, then set boot drive in Sys Prefs to this Accelsior volume. It's all you can do. Some PCIe cards increase boot time a bit. Accesior is one of them according to users reviews.
  4. scottrichardson macrumors 6502

    Jul 10, 2007
    Ulladulla, NSW Australia
    Not entirely surprised - the Accelsior that I had was SLOWER with small file data blocks like 4KB up to 64KB. It was only with larger data chunks where the Accelsior could be faster than a standard SSD - noting that the onboard RAID controller of the Accelsior (it has 2 blades in RAID 0) isn't so great at small data blocks.

    This is why I sent mine back and got a Sonnet Tempo Pro SSD PCI Card and stuck 2 x 512GB Samsung SSD 840 Pros on it.

    It could be that the Accelsior is just plain slower at loading all the OS X files required for boot?
  5. Demigod Mac macrumors 6502a

    Apr 25, 2008
    Reset PRAM as many mentioned (Cmd Option P R at startup, release after the screen flashes black after the first chime), then select it as the designated boot drive in Startup Disk. An Accelsior should load OS X in literally 2-3 seconds or so, that is, when you see the spinning icon under the Apple logo.

    Also install the Accelsior driver to prevent shutdown and sleep issues:
  6. iPadPublisher thread starter macrumors 6502

    Apr 14, 2010
    Installed the driver right away, upon install. Good there. Tried the PRAM (NVRAM now, technically) reset today and POOF... startup speeds now beat the prior installed OWC SSD drive from 49.8 to 41.8 seconds, so 16% faster. Meh, but I'll take it. Thanks to all who suggested that!

    I'm seriously considering the Sonnet Tempo Pro SSD though... I was hoping for the much faster speeds OWC quotes on their web site, which I now am irritated to find considerably exaggerated. Theoretical maximums, as some have suggested, but far from real world performance.
  7. derbothaus macrumors 601


    Jul 17, 2010
    You have the much faster speeds OWC quotes. Do a sequential bench test and you will see it. The problem is a boot drive does not use sequential bandwidth almost at all. The advertising is very misleading with the big sequential numbers. SSD's main strength is the 120-200MB/s of 4K random writes that a simple SATA2 SSD can do. So interface link on PCI for boot disk is not the best use of ones money. Just boot off the native SATA bus and save your cash. It'll boot just as fast and run your OS the same as a PCI one rated at 120000MB/s. Apple is using this as well on the Air and Mac Pro. It isn't false, it just does not matter very much.
  8. scottrichardson macrumors 6502

    Jul 10, 2007
    Ulladulla, NSW Australia
    You WILL get ~800MB a second - but only if you're transferring a large files that aren't compressed!

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