eGPU Testing

My current setup:
2018 MacBook Pro 2.9 GHz i9 with 32GB Ram / Mojave 10.14
Razer Core X with AMD Sapphire RX580 8GB Card
"Prefer External GPU" is checked (New Feature in Mojave).The GUI is running on a 1080p monitor connected to the eGPU. Two Outputs going into an E2. First output is DisplayPort 3840x1200@60 and the second output is 1920x1080@60 via HDMI.

Looping two 10 second ProRes 422 videos and about every 30 seconds, the frames per second drop from 60 fps to around 35 fps then back to 60 fps. Would anyone know what would be causing this? It';s pretty consistently happening almost every 30 seconds.


  • Currently trying on Millumin 3 beta version. Was also happening on Millumin 2.

  • Think I found the culprit. Mojave was changing the desktop in the background. Will continue testing.
  • Hello @HardwickM,

    Thank you for the info.
    Let us know the results about your eGPU. Also, be sure to read our post about good practices here.

    Best. Philippe
  • Frame rate still drops during playback. Goes down to around 40fps and comes back to 60fps randomly. But I am still running videos from my main drive as I don't have access to a TB3 external drive. This is if I am running one video on one canvas or four videos on four canvases. I don't think Apple is quite there yet with their support for eGPU's.
  • Hello @HardwickM,

    Did you try to use HAP or H264 codec ?
    They should more suitable than ProRes-422, especially to be transfered from your drive to the eGPU.

    I'm not sure a TB3 external would change anything, but let us know it it does. Thank you.

    Best. Philippe
  • I converted them to HAP and had the same results weather I had one video running on one canvas or four videos running on four canvases. I think the problem lies with Apple and the way the handle the throughput of the TB3 pathway. I'll give H264 a try when I get to testing again.

  • Hello,
    Is the "option prefer externa"l  in Mojave a solution to get rid off having a screen attached on the eGPU with Millumin on it?
    I mean in terms of performances...
    This could be handy because it would gave us one more output.
    Best regards

  • Hello @generalh,

    This option of Mojave won't change your hardware : it's still heavy to transfert data from the external GPU (making all the calculations) to the internal GPU (to display the results on the internal display). 
    We wrote an article here to explain what's happening in your hardware.

    However, we recently have been testing a lot eGPU with Millumin recently, trying to offer the best experience possible.
    We talk about this on Millumin Operators group here. If you don't have a Facebook account, here is the post :

    We implemented a few features in Millumin to improve eGPU support, as well as measuring its performance.
    Please download and try this beta version 3.11.k2

    In brief :
    - you just have to run Millumin and it automatically select the best GPU (it requires macOS 10.13.4 or macOS 10.14)
    - it selects the best GPU even it you're launching Millumin on a screen connected to another GPU
    - we added a tab "System" to the monitor (see "Monitor" in "Window" menubar), so you could track CPU/RAM/GPU usage

    Let us know your thoughts and experiences.
    Thank you.

    On our side, we tested the standard eGPU from Apple (Sonnet Breakaway
    Box + Radeon RX 580) : from the latest MacMini (the first and lowest
    model), we're able to play 4 x 4Kp60 movies on 3 x 4Kp60 displays + a
    1080p display for Millumin's interface. We used HAP codec for optimal
    performances, and FPS was steady at 60fps.
    On a MacBookPro Touchbar,
    the results are the same, and we even were able to run Millumin's
    interface on internal display, but with "disable workspace" option
    enabled (so data transfert is minimum between internal GPU and external

    In brief : you can display Millumin's interface on an internal display, but you should activate the option "disable workspace" so it doesn't affect the performance. However, ideally, use a display connected to your eGPU.
    Best. Philippe

  • HI - Millumin responded to a similar issue that I'm having on an iMac Pro with Mojave. 

    "Your issue seems to be related to a bug we submitted to Apple : this affects a few configurations on macOS Mojave 10.14, and this doesn't affect only Millumin but also other softwares relying on GPU (Resolume for example).

    We provided a lot of info to Apple engineers, we chatted a bit with them, and now we're waiting for their reply.
    Hopefully this gonna be fixed soon.

    Could you come back to macOS 10.13.6 and let us know if the problem persists?"
  • edited July 2019
    I just ran across this thread - and have a similar setup.
    Razer eGPU with WX9100 connected to newest Mac Mini.
    Mojave 10.14.5
    Millumin 3.11q
    5 outputs to E2, 1 for local display.

    If eGPU is connected to e2, the mouse stutters and I see frame rate issues described above.
    If I disconnect the HDMI's to e2 - its fine.
    I tested this output scenario in the shop, but not with E2 - using single monitors - and had no issues.
    Is this fixed in 10.14.6? Or is this an E2 EDID issue?

    I'm in the middle of show and this is painful.

  • This issue (introduced in Mojave) have been fixed by Apple in latest and official macOS 10.14.6 update.
    update of Millumin will display a message to recommend you to update
    your macOS in this case (this message is already displayed in latest
    Millumin beta 3.12.m).

    Best. Philippe
  • edited July 2019
    i'll give a shot on my backup machine. thanks
    [EDIT: Seems to be solid now.]

    My Laptop (trial license only for testing) is on 3.12l and shows no update available to M,

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