SSD in MP 5.1... not expected results

Discussion in 'Mac Pro' started by JMVB, May 28, 2016.

  1. JMVB macrumors member

    JMVB

    Joined:
    May 16, 2016
    #1
    I have the MP 5.1 of my signature.
    It had a Crucial M4 512gb SSD

    And I have the MBP 15@ of my signature.
    It had a Crucial MX100 512 SSD

    Both with Yosemite 10.10.5

    For curiosity, I did a Blackmagic speed test

    The MP about 250 mb/s in read and write :/
    The MBP about 510 mb/s in read and write :O

    I'd a research in the net and right, the MX100 is faster than M5
    Ok, i'll swap the disk, I think to myself

    Back up both SSD, swap it and clone it

    The MP 260 mb/s in read and write.
    The MBP 260 mb/s in write and 510 mb/s in read...

    Ok, clean installation, I think to my self

    And.... the same result, 260 mb/s in read and write.

    Why the MP have worst performance than less powerful laptop?

    The SSD is in the 1º slot, and I have a 1 TB HD in the 2º slot and a 2 TB HD in the 3º slot
     
  2. throAU macrumors 601

    throAU

    Joined:
    Feb 13, 2012
    Location:
    Perth, Western Australia
    #2
    Your Mac Pro has SATA 2 ports (not SATA3, which was new in 2011 i think?).

    Those results are in line with expectations.
     
  3. JMVB thread starter macrumors member

    JMVB

    Joined:
    May 16, 2016
  4. throAU, May 28, 2016
    Last edited: May 28, 2016

    throAU macrumors 601

    throAU

    Joined:
    Feb 13, 2012
    Location:
    Perth, Western Australia
    #4
    Well "OK" is subjective.

    Are they fast enough for you? Because it's all you're going to get with that setup.

    SATA 2 tops out at 3 Gigabit/sec. Which is a theoretical 300 megabytes/sec without any protocol overhead. Real world throughput is what you are seeing, SATA3 is 6 gigabit and tops out around 500MB/sec, which is what you see in the more recent Macbook.

    You are entirely storage controller throughput limited. Your only options from here to get faster are to get a SATA 3 PCIe card (or M.2 card, no idea if either option is supported by OS X or not though), or run a PCIe SSD. Or run RAID with multiple SSDs.
     
  5. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #5
    100% normal, as the others pointed out, the SSD is caped at the SATA 2 speed, which is around 250MB/S in real world.

    If you didn't feel any problem in real world usage, that most likely means everything is OK.
     
  6. Draeconis macrumors 6502a

    Joined:
    May 6, 2008
    #6
    SATA-III and M.2 via PCIe adapter totally compatible. With M.2 ensure the SSD is AHCI though; some cards (SM951-NVMe, Samsung 950 Pro, Intel 750 series) use NVMe, a new storage protocol that Mac Pros don't support.

    One chap did post a generic NVMe storage device driver, but this stopped working with more current OS X releases, he hasn't been around to offer a fix, and this still wouldn't allow it to be a boot device.
     
  7. JMVB thread starter macrumors member

    JMVB

    Joined:
    May 16, 2016
    #7
    It is there other sata iii option without using a pci-e slot?

    I have not empty splots... I need it all..

     
  8. DPUser macrumors 6502a

    Joined:
    Jan 17, 2012
    #8
    You probably won't notice the difference in boot drive applications, since reads are very small and SSD is the limiting factor. Large file read/write is another matter.
     
  9. throAU macrumors 601

    throAU

    Joined:
    Feb 13, 2012
    Location:
    Perth, Western Australia
    #9
    Unfortunately, no.
     
  10. flowrider macrumors 601

    flowrider

    Joined:
    Nov 23, 2012
    #10
    Your results are as expected. My results on a cMP 5,1:

    1. SSD in SATA Bay
    [​IMG]

    2. SSD in Apricorn Velocity Duo
    [​IMG]

    3. SM951 on WINGS PX1
    [​IMG]

    Lou
     

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  11. teeck2000 macrumors regular

    Joined:
    Jun 20, 2009
    #11
    Well you could possibly use the Mini PCie slot where the Airport card is, but then then no wifi if you needed that.
     
  12. scott.n macrumors 6502

    Joined:
    Dec 17, 2010
    #12
    There are USB 3 + SATA III combo cards, though I don't have personal experience with using one in a Mac Pro.

    If one of your existing cards is an USB 3 card, then you could consider swapping it for a combo card.
     
  13. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #13
    That's a PCIe x1 Gen 1 slot, only 0.3GB/s bandwidth, Exactly the same as the SATA 2 slot bandwidth. Impossible to make it SATA 3.
     
  14. haralds macrumors 6502

    haralds

    Joined:
    Jan 3, 2014
    Location:
    Silicon Valley, CA
    #14
    I use two Caldigit FASTA-6GU3 Pro cards for my SSDs with good results - http://www.caldigit.com/Fasta-6GU3pro/
    I also use their USB 3 slots, but like all of them for the cMP, they are not bootable.

    The Caldigit boot both OS X and BootCamp.
     
  15. teeck2000 macrumors regular

    Joined:
    Jun 20, 2009
    #15
    Ahh okay I thought it was Pcie x2.
     

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