Waiting for Thunderbolt 4 thread (eGPU folks, this might interest you)

Discussion in 'Buying Tips and Advice' started by Riven, Jun 5, 2017.

  1. Riven macrumors newbie


    Sep 12, 2016
    SF, CA
    With Apple making external GPUs (eGPUs) a reality in macOS 10.13, I've decided to wait as long as I need to until Apple releases a computer with Thunderbolt 4, specifically on a MacBook Pro. (32 GB DDR4L RAM might come as well by then.) If you look at my short post history, you might doubt me because at first I thought I was going to buy a Razer Blade Pro after Apple's dismal showing of rMBPs (imo) and then just today I said I was going to wait for the Mac Pro. In my mind native support for external GPUs on macOS was an absolute pipe dream. But then I ran across the external GPU Development Kit, and I'm absolutely locked into Apple for my next computer because of this.

    Currently, the Alpine Ridge TB3 controller has 40Gb/s throughput per port, and while there is enough bandwidth to run a GPU decently, think about the compute-heavy/high-end GPUs like the GTX 1080 or any workstation GPU – they will certainly run into the TB3 bottleneck. (I haven't done enough in-depth research to know how much a GPU's performance will be affected.)

    Since bandwidth has doubled with every iteration of TB, it's sensible to think TB4 will have 80Gb/s throughput per port. With that, I'll finally be able to run a gaming or workstation-class GPU from a laptop and have the setup of my dreams - portability when I need it; and graphics, compute power, a docking station, and charging when I need it at home, all through one cable.

    If you've been waiting for external GPUs, or something like this, wait for TB4 because high-end GPUs might still be significantly bottlenecked - I remember reading a long while ago that TB2 could run a GTX750 at only 85% of max performance. I'm willing to wait up to 3 years from date of posting. Perhaps it might come out earlier, who knows.

    Thoughts? Comments? Estimations on % of GPU performance lost due to TB3/hypothetical TB4 bandwidth constraints?
  2. Kiro macrumors member


    Sep 15, 2015
    Germany, Leipzig
    Maybe it works with two TB3 cables for 80gb/s ?
    I think that I've read that TB3 should be enough for a 1080ti.
  3. anton_usa macrumors newbie

    May 11, 2017
    Not necessarily. TB1 to TB2 didn't double the bandwidth. TB2 simply aggregates the two channels of TB1, which is the same total bandwidth.

    2011 - TB1
    2013 - TB2
    2016 - TB3

    Which shows exponentially increased time between releases, so you might be waiting 4+ years for a consumer product with TB4.
  4. Samuelsan2001 macrumors 604

    Oct 24, 2013
    Unless you are running two graphics cards in you eGPU in SLI then currently the bandwidth of TB3 is way more than enough for you. As it will take 4 years for AMD and NVIDIA to upgrade their architecture again then I doubt there will be anything that won't run on a TB3 eGPU before TB4 comes out anyway, you really are waiting for no good reason.
  5. Fishrrman macrumors G4

    Feb 20, 2009
    What's the timetable for tbolt 4?
    Two years?
    Three years?
    How "long" are you willing to wait?

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