iMac 5k: PCI-e or SSD flash

Discussion in 'iMac' started by Chocomonsters, Oct 16, 2014.

  1. Chocomonsters macrumors regular

    Joined:
    May 22, 2007
    #1
    Mac Mini can be config with PCI-e memory. Is iMac 5k flash storage PCI-e or SSD?
     
  2. ngaham, Oct 16, 2014
    Last edited: Oct 16, 2014

    ngaham macrumors regular

    ngaham

    Joined:
    Sep 8, 2011
    #2
    I was wondering this myself also. I have been looking for it online, but can't find it yet. I wonder if you uses PCI-E as the Pro Retina does.

    Actually just found the answer HERE. It's PCI-E (fifth paragraph down)
     
  3. shokunin macrumors regular

    Joined:
    Jun 7, 2005
    #3
    It's both, PCIe is the Interface, (Solid-State Disk) SSD is flash storage. It is not a SATA interface, which is currently limited at 6gb.
     
  4. Jack40 macrumors newbie

    Joined:
    Jul 26, 2011
    #4
    The new Imac 5k has sata SSD

    The new Imac 5k has sata SSD.
     
  5. tillsbury macrumors 65816

    Joined:
    Dec 24, 2007
    #5
    No, the link above clearly states PCI-e SSD...
     
  6. Serban Suspended

    Joined:
    Jan 8, 2013
    #6
    PCIe-e SSD
    i tested today in the apple store read speed up to 630mbs-730mbs
     
  7. xmichaelp macrumors 68000

    xmichaelp

    Joined:
    Jul 10, 2012
    #7
    Can you give a short description of the new iMac? Was it smooth? How gorgeous was it? Thanks. :)
     
  8. KenAFSPC, Oct 18, 2014
    Last edited: Oct 18, 2014

    KenAFSPC macrumors 6502a

    Joined:
    Sep 12, 2012
    #8
    Unfortunately, the iMac 5k includes an older 2-lane PCIe Sandisk SSD, at least in the 256GB configuration, which means SSD performance is more comparable to a SATA SSD than a PCIe SSD.

    Ideally, the iMac 5K would include a 4-lane PCIe M.2 PCIe slot, as found on the latest PC motherboards, so we could upgrade to a newer, faster SSD.

    For the non-techies, the storage hierarchy is as follows:

    (1) M.2 PCIe 3.0 X4 (up to 32Gbps theoretical or 3.2GBps real world max)
    (2) M.2 PCIe 2.0 X2 (up to 10Gbps theoretical or 1.0GBps real world max)
    (2) SATA Express (up to 10Gbps theoretical or 1.0GBps real world max)
    (3) SATA 3 (up to 6Gbps theoretical or 600MBps real world max)
    (3) M.2 SATA 3 up to 6Gbps theoretical or 600MBps real world max)
    (4) M.2 PCIe 2.0 X1 (up to 5Gbps theoretical or 500-550MBps real world max)

    Again, the Sandisk 256GB SSD in the iMac 5K is an older M.2 PCIe 2.0 X2 (X2 = 2 lane) device. The theoretical max for that interface is 1Gbps, although the Sandisk drive uses older technology so its actual throughput is 600-700Mbps.

    You must have both a motherboard and a SSD that supports the same interface to achieve a given level of performance. If you stick a M.2 PCIe 2.0 X1 SSD into a M.2 PCIe 3.0 X3 slot, then you will get a max of 500-550MBps, not 3.2GBps. Similarly, if your motherboard only has a M.2 PCIe 2.0 X2 slot, then you will never achieve more than ~1.0GBps no matter what drive you use.

    Samsung just released ithe successor to the XP941 PCIe SSD found in the newest MacBooks. This device, the SM951, is a M.2 PCIe 3.0 X4 SSD with NVMe that delivers 1600MBps throughput (assuming a motherboard with a a M.2 PCIe 3.0 X4 slot) with much lower latency, or nearly 2.5X the real world performance of the 256GB SSD in the iMac. I'm hoping Apple opted for this drive in the 1TB SSD configuration; if they did, it would be a worthwhile upgrade over the 256GB model.
     
  9. mikeboss macrumors 65816

    mikeboss

    Joined:
    Aug 13, 2009
    Location:
    switzerland
    #9
    if the 1.0 TB PCIe SSD in the 5K iMac (have one on order) will be connected using only 2 lanes, I think I will return it. this would be inacceptable. I now have a 4-lane XP941 running in my classic Mac Pro and I do not want inferior performance.
     

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