Late 2016 MacBook Pro 13" + Thunderbolt 3 eGPU

Discussion in 'MacBook Pro' started by theitsage, Oct 28, 2016.

  1. rwstgermain macrumors member

    Joined:
    Sep 15, 2016
    #51
    How is the switching between dGPU and eGPU preformed? Automatically once the eGPU is detected? I have been wondering if the Razer Core, which naively utilizes Thunderbolt 3, would just work within bootcamp.
     
  2. cube macrumors P6

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    May 10, 2004
    #52
    It seems you have to just hope macOS will select the right GPU.

    Now it is doing it fine with iGPU, AMD 6xxx and AMD RX installed.
     
  3. theitsage, Oct 31, 2016
    Last edited: Nov 2, 2016

    theitsage thread starter Suspended

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    Aug 28, 2005
    #53
    My understanding of a Mac with multiple GPUs in Mac OS environment is as followed:

    - OpenCL apps (such as FCPX, Luxmark, Handbrake,..) are able to detect and make use of all GPUs.
    - OpenGL apps (such as AutoCAD, Adobe CC, video games,...) run on the monitor through which the GPU is connected.

    On a headless Mac like the Mac Pro, it's very simple to visualize how this GPU selection process works. Mac laptops with both iGPU and dGPU rely on Automatic Graphics Switching. I'm not smart enough to give a definitive explanation on how this works with an eGPU. I know using an external monitor is one sure way to take advantage of an eGPU for OpenGL/Metal tasks.
     
  4. cube macrumors P6

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    May 10, 2004
    #54
    A certain setup might not be running properly. I had the CPU or internal GPU rendering and displaying via the eGPU at some point.
     
  5. theitsage, Oct 31, 2016
    Last edited: Nov 2, 2016

    theitsage thread starter Suspended

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    Aug 28, 2005
    #55
    I learned something new about ThunderBolt 3 bandwidth and how Apple might have crippled these 2016 MacBook Pros - https://thunderbolttechnology.net/sites/default/files/Thunderbolt3_TechBrief_FINAL.pdf

    Apple talked about Thunderbolt 3 capable of 40 Gbps but due to the single Thunderbolt chip in the base MBP, each USB-C port can only run at 20 Gbps max. This is the same max bandwidth as Thunderbolt 2.

    I would guess the 13" touchbar MacBook Pro is the same way - two Thunderbolt 3 chips handling 4 ports.
     
  6. Clint_Barton macrumors 6502

    Joined:
    Oct 23, 2016
    #56
    The information from apple says that the base-no touchbar provides full performance to both TB3 ports, while on the 13-touch bar, only the two left hand TB3 ports operate at full speed, while the right two are limited, the 15in has full performance on all ports.

    From apple
    "
    Thunderbolt 3 data speeds per MacBook Pro port

    Late-2016 MacBook Pro models vary slightly in the data speeds they provide to each Thunderbolt 3 port.

    MacBook Pro (15-inch, Late 2016) delivers full Thunderbolt 3 performance on all four ports.

    MacBook Pro (13-inch, Late 2016, Four Thunderbolt 3 Ports) supports Thunderbolt 3 at full performance using the two left-hand ports. The two right-hand ports deliver Thunderbolt 3 functionality, but have reduced PCI Express bandwidth.

    Always plug higher-performance devices into the left-hand ports on MacBook Pro (13-inch, Late 2016, Four Thunderbolt 3 Ports) for maximum data throughput.

    MacBook Pro (13-inch, Late 2016, Two Thunderbolt 3 Ports) delivers full Thunderbolt 3 performance on both ports.

    About USB speed
    For USB devices, all late-2016 MacBook Pro models deliver USB 3.1 Gen 2 (10 Gbps) performance on all Thunderbolt 3 ports.

    Use a USB-C to USB adapter to connect a USB-A device or cable to a Thunderbolt 3 port on your MacBook Pro. Use a USB 3.1 (USB-C to USB-C) cable to connect a USB-C device."
     
  7. theitsage thread starter Suspended

    Joined:
    Aug 28, 2005
    #57
    The support document talks about reduced PCIe lane. Here's what I'm seeing in Thunderbolt under System Information.

    Screen Shot 2016-10-31 at 7.01.37 PM.png
     
  8. Zackmd1 macrumors 6502a

    Joined:
    Oct 3, 2010
    Location:
    Maryland US
    #58
    That would be absolutely amazing if true..... Also false advertising on Apple's part. Maybe this could just be an oversight in the hardware browser and the TB3 ports do indeed run at 40gb/s but its just reporting 20? Maybe? I would want to believe that over apple crippling the base model further but who knows anymore....
     
  9. rwstgermain macrumors member

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    Sep 15, 2016
    #59
    Maybe requires two devices connected using a Active TB3 cable?
     
  10. cube macrumors P6

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    May 10, 2004
    #60
    Which TB cables are not active?
     
  11. theitsage thread starter Suspended

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    Aug 28, 2005
    #61
    Someone has tried a Razor Core using a TB3 cable and see the same result. - http://imgur.com/hTrMsKY
     
  12. blackberrycubed macrumors 6502a

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    Feb 26, 2013
    #62
    this is not making sense to me, apple would not lie about something like this.
     
  13. killawat macrumors 65816

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    Sep 11, 2014
    #63
    Thanks again for the quick reporting. Akitio needs to send you a Node so you can convince us to buy it.
     
  14. RocketHopper macrumors newbie

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    Oct 18, 2016
    #64
    eGPUs working makes or breaks the MBP purchase for me, thanks for looking into this guys
     
  15. Zackmd1 macrumors 6502a

    Joined:
    Oct 3, 2010
    Location:
    Maryland US
    #65
    Apple has gone to a new low with these MacBook's but false advertising is something else entirely.... There must be another answer.... I hope there is another answer.
    --- Post Merged, Oct 31, 2016 ---
    eGPUs seem to work but now the question seems to be whether or not they will run at TB3 40gb/s or the older TB2 standard of 20gb/s which is what the hardware is reporting....
    --- Post Merged, Oct 31, 2016 ---
    I started a thread here: http://forums.macrumors.com/threads/calling-all-2016-rmbp-owners.2011425/

    I want to see if we can get more owners to report in on what their hardware browser says and if we can get anyone to test with actual TB3 accessories.
     
  16. tryrtryrtryrt Suspended

    Joined:
    Sep 10, 2016
    #66
    Could you tell exactly what cable are you using? AFAIR only optical cable which is not capable of transferring energy can achieve 40 Gbps. All others can only achieve 20 Gbps. Need to dive into Thunderbolt 3 specs though, I'm not sure.
     
  17. rwstgermain macrumors member

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    Sep 15, 2016
    #68
  18. theitsage thread starter Suspended

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    Aug 28, 2005
    #69
    2016 13" MacBook Pro --> Apple TB3 to TB2 Adapter --> Apple Thunderbolt 2 cable --> AKiTiO Thunder2 eGPU

    I checked Thunderbolt in System Information on a mid 2015 15" MBP and a late 2015 27" iMac 5K.

    Screen Shot 2016-11-01 at 6.01.08 AM.png

    Screen Shot 2016-11-01 at 7.13.34 AM.png
     
  19. RocketHopper macrumors newbie

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    Oct 18, 2016
    #70
    I made that thread :)
     
  20. Clint_Barton macrumors 6502

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    Oct 23, 2016
    #71
    Could you link that thread?
     
  21. RocketHopper macrumors newbie

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    Oct 18, 2016
  22. rwstgermain macrumors member

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    Sep 15, 2016
    #74
  23. theitsage thread starter Suspended

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