Anyone try Samsung 970 Pro NVME in a Mac Pro?

Discussion in 'Mac Pro' started by krakman, May 20, 2018.

  1. krakman macrumors regular

    Joined:
    Dec 3, 2009
    #1
    Hi,

    I just noticed Samsung released the latest incarnation of it NVME SSD:

    http://www.samsung.com/semiconductor/minisite/ssd/product/consumer/970pro/

    The spec says it runs NVME version 1.3 (there is a driver for Windows)

    https://www.anandtech.com/show/11436/nvme-13-specification-published-new-features

    Questions...

    Does anyone know if high Sierra support the 1.3 spec?

    Will it fall back to 1.2 spec if installed in a system with out the newest drivers?

    Neither the cMP nor the nMP fully utilise the transfer speeds available so the main benefit of the 970 seems to be lower power draw = less heat, so it should be a good fit for the trashcan.

    I'm after a 2TB stick so maybe I will just get the 960 pro as I know this works.
     
  2. MarkJames68 macrumors 6502

    MarkJames68

    Joined:
    Sep 24, 2017
    #2
    I haven’t noticed any heat issues with the 960 Pro, but I mounted a stick on heat sink just in case.
     
  3. XNorth macrumors regular

    XNorth

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    Feb 23, 2018
    Location:
    United States
    #3
    The 970 EVO looks to be the better buy vs the PRO.
     
  4. MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #4
    Except that the "Pro" models don't slow down during sustained, large transfers AFAIK.

    But I'm very happy with my 960 EVO. I just wish that teh 500gb models were cheaper.
     
  5. noodle654 macrumors 68020

    noodle654

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    Never Ender
    #5
    I put the 970 EVO in my 2014 Mini it runs great, haven’t benchmarked it against the 960 EVO in my nMP.
     
  6. MIKX, May 21, 2018
    Last edited: May 22, 2018

    MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
    Location:
    Japan
    #6
    I'm getting 1365 mb/sec write & 1478 mb/sec read in my 4,1>5,1 cMP 960 EVO 256gb.
    I'm more than happy with that compared to SATA II speeds.
     
  7. atonaldenim macrumors newbie

    Joined:
    Jun 11, 2018
    #7
    Nice, which slot and which PCIe card are you using?
     
  8. Catsolo macrumors newbie

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    Aug 22, 2018
    #8
  9. handheldgames macrumors 68000

    handheldgames

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    Apr 4, 2009
    Location:
    Pacific NW, USA
    #9
    There is a reason Reviews don't put this up against the 970Pro. It can't compete with it. It's mixed read/write performance, along with many other results, quickly falls behind the pack.

    https://www.anandtech.com/show/13112/the-adata-sx8200-gammix-s11-nvme-ssd-review/7
     
  10. MIKX macrumors 6502a

    MIKX

    Joined:
    Dec 16, 2004
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    Japan
    #10
    For some reason which I do not understand. . it ( 960 EVO )runs faster in slot 3.
     
  11. Matty_TypeR macrumors regular

    Matty_TypeR

    Joined:
    Oct 1, 2016
    #11
    I wonder if slot 1 16X GFX card and slot 2 also 16x share an IRQ when you have your PCIe card in slot 2 does your GFX card report at 8X
     
  12. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #12
    Share IRQ??? I don't think there is any IRQ in a PCIe connection but only MSI.

    Anyway, since you mentioned about x8, x16 etc. I think you mean share PCIe lane.

    1) Slot 1 and 2 are independent. Devices can negotiate at 5GT/s x16 in both slot 1 and 2 at the same time regardless if it's a GPU or SSD or any other device. And each of them has max 8.0 GB/s throughput.

    2) Even if share lane, as long as via a switch, both slots will still capable to negotiate at 5GT/s x16 simultaneously, but just the total throughput will be limited to 8.0 GB/s (this is actually the case of slot 3 and 4 on the 5,1. They use the same PCIe 2.0 x4 lane).
     
  13. Matty_TypeR macrumors regular

    Matty_TypeR

    Joined:
    Oct 1, 2016
    #13
    Yes sorry I meant PCIe lane speed, not IRQ that's PC problems. I have an angel bird PCIe with AHCI drive in slot 4 and another PCIe card in slot 3 with Samsung NMVe drive, both report 5GT's speed 4 X. I was wondering if the Mac uses the same system as a PC where sometimes you get a shared lane which can impact speed. On the PC its called Interrupt request, which can be problematic with some conflicts between PCIe devices. but as you say the Mac doesn't use this my thinking is irrelevant as to why it would be faster in slot 3 for MIKX

    thanks for the heads up on Mac PCIe lanes though. on my PC Asus edition 10 I had problems with the onboard M.2 slot causing the titan GFX card in slot 1 going to 8x and not 16X and it was a priority setting in the bios. Not that you have a bios to view on a Mac of course.
     
  14. crjackson2134, Sep 9, 2018
    Last edited: Sep 9, 2018
  15. h9826790, Sep 9, 2018
    Last edited: Sep 9, 2018

    h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #15
    It seems you are heading the wrong direction.

    a) For firmware 138.0.0.0.0

    Slot 1 - PCIe 2.0 x16 (max 8GB/s)
    Slot 2 - PCIe 2.0 x16 (max 8GB/s)
    Slot 3 - PCIe 2.0 x4 (max 2GB/s)
    Slot 4 - PCIe 2.0 x4 (max 2GB/s)

    HOWEVER, slot 3 and 4 share use the same PCIe 2.0 x4 lane, therefore, the COMBINE throughput still max at 2GB/s)

    So, your setup can never fully utilise both SSD at the same time. A Samsung NVMe can easily use up all 2GB/s throughput (real world transmission speed is about 1500MB/s). Then nothing left for the Angel bird.

    When the Angel bird demand some bandwidth, the Samsung will be slowed down.

    b) For firmware 0089.B00 or earlier

    Slot 1 - PCIe 2.0 x16 (max 8GB/s)
    Slot 2 - PCIe 2.0 x16 (max 8GB/s)
    Slot 3 - PCIe 2.0 x4 (max 2GB/s)
    Slot 4 - PCIe 2.0 x4 (max 2GB/s)

    Slot 3 and 4 still share use the same PCIe 2.0 x4 lane via a build in PCIe switch.

    HOWEVER, without a PCIe switch, only very few PCIe 3.0 device can correctly negotiate at PCIe 2.0 speed on the cMP, but auto fall back to PCIe 2.0 speed.

    Therefore, a PCIe 3.0 x4 NVMe SSD can only negotiate at PCIe 1.0 x4 in slot 1 or 2. Make it limited to 1GB/s throughput, and real world speed maxed at about 750MB/s.

    But if you install the same SSD in slot 3 or 4, due to there is a build in PICe switch, it can correctly negotiated at PCIe 2.0 x4, and max at 2GB/s (1500MB/s real world).

    Mac is just a subset of Intel PC, absolutely nothing special in those IRQ, MSI, share lane.... However, AFAIK, IRQ simply not exist in PCIe connection. IRQ does exist in PCI connection, but not PCIe connection. And that has nothing to do about PCIe lane sharing even on a normal PC.
     
  16. Matty_TypeR macrumors regular

    Matty_TypeR

    Joined:
    Oct 1, 2016
    #16

    Thanks for the explanation, so in affect although with both drives in slot 3 and 4 I suffer no loss of performance because of the PCIe switch. I never use both at the same time, diffrent boot drives.

    very well explained, thanks! I was barking up the wrong tree.
     

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