Thunderbolt & External GPU Questions

Discussion in 'MacBook Pro' started by MacMusician33, Sep 4, 2015.

  1. MacMusician33 macrumors newbie

    Aug 29, 2015
    Hi Everyone,

    It has been mentioned in some posts that Thunderbolt 3 will officially support external GPUs.
    However, from what I have seen in videos and other posts online, Thunderbolt 1 and 2 also share this capability. So what exactly is it about Thunderbolt 3 that makes this feature unique?

    I have also read that Thunderbolt 3 will also be backwards compatible with older models.
    Does this mean that my 2011 MacBook Pro will support the new eGPUs?

    Also, is it true that OS X is unable to output graphics on the laptop screen and has to output to an external monitor while Windows has this ability? I would still ideally like to use my MacBook monitor if possible.

  2. Samuelsan2001 macrumors 604

    Oct 24, 2013
    Well what it means is that they will be able to be plug and play your eGPU with no EFI issues etc, the firmware is already included in the port basically, of course no one is making one yet so you still have to spend many hundreds of dollars building your own.

    Backwards compatable just means that thunderbolt 1 and 2 products and cables will work fine with it. (Although if it comes in USB-C format it'll need an adaptor.)

    As far as I know you can already use an external to power the macbook screen (I'm sure I've seen it on imacs) but if indeed you can't that will be down to what apple supply in future OSX updates.
  3. Freyqq macrumors 601

    Dec 13, 2004
    Official support just means that Intel will support that use case. Apple may get onboard too and provide proper driver support. Thunderbolt 2 already works for this, and i'd expect Thunderbolt 3 docks to be backwards compatible with Thunderbolt 2. Thunderbolt 3 has better bandwidth, so perhaps the performance is sufficient for Intel to want to support it.

    I am really looking forward to buying an external GPU one day. It would extend the life of my computer significantly.
  4. MacMusician33 thread starter macrumors newbie

    Aug 29, 2015
    I am also greatly looking forward to eGPUs for the same reason. My 2.0GHz i7 15" MBP from 2011 is still fairly powerful by today's standards. If I could upgrade to an eGPU as powerful as perhaps a GTX 750 Ti then I would be perfectly satisfied with my Macbook Pro.
  5. cycledance Suspended

    Oct 15, 2010
  6. Fl0r!an macrumors 6502a

    Aug 14, 2007
    For TB1 & 2 this has to be achieved with some OS X hacks, and I'm 99% certain that won't change with TB3. The Thunderbolt bus might easily be able to connect a eGPU on hardware level, but Apple might still make things complicated with half-baked software support. And they will, lastely they want to sell new Macs instead of helping you to get some more years out of your old machine.

    That's true, netkas has confirmed that.
  7. MerlinX10 macrumors newbie

    Sep 2, 2015
    I have the 2011 17" and was wondering if my i7 would power an eGPU for a (somewhat) mobile VR setup.

    Well, I just finished booting Windows 10 with both GTX 970 and internal Radeon 6750M working. Amazing scores on 970 on external monitor.

    I'm dual booting and running Windows 10 in bios (legacy) boot mode with a regular bootcamp upgrade from Windows 7.

    Akitio Thunder 2 PCI-e (powered from PSU using barrel adapter)
    Rosewill gold PSU
    EVGA GTX 970 FTW+ plugged directly into Akitio (no riser), and latest Nvidia Driver (364.51 win10 64bit). Macbook Pro has all bootcamp drivers installed and working (internal Radeon 6750M fully working, sound, etc).

    Booted into Windows 10 with eGPU fully working. Ran several Steam VR tests and score either very top of "Capable" (yellow bar), or into low end of "Ready" (green bar).

    Only drawback is I have to boot using the timing method. Have Thunderbolt cable plugged in, but PSU powered off. Boot holding option to the boot selection screen. Hit enter on Windows, wait 3 seconds, and power on PSU. Works reliably for me. Sometimes I miss the timing, but just try again. It's like a 3 1/2 second wait for me before hitting power switch. Then I'll see windows boot cursor and know I got it.

    First install: Boot with eGpu plugged in. Download Nvidia drivers. It should detect card and install. If not, try again.

    First boot after installing drivers: Device manager showed 970 installed and active, but no image on external screen. Used Win+P to extend desktop and to my surprise external screen came alive and is surprisingly fast running benchmarks.

    Valley benchmark (default install settings -- high -- system res -- dx11) pulled a surprising 3325 score, 79.5 fps (1920x1080 monitor)
    Steam VR high end of capable, sometimes tests into the fully ready zone. No frames CPU bound.
  8. MerlinX10 macrumors newbie

    Sep 2, 2015
    So, followup to this. HTC Vive is amazing! The 2011 MBP 17" runs many things just fine with gtx 970 in Akitio Thunder 2 eGpu under Win10 (ptui!). Recent performance improvements have made The Blu run good. The Lab is excellent. Only thing still stuttering is Cloudlands VR mini golf, however performance improvements are obvious there too. Software optimizations are really making a difference. Bandwidth of TB1 is clearly the bottleneck. Curious what a 1070 with new hardware optimizations what do, or if the bandwidth limitation just cannot be overcome.

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