How to get full H2D TB3 bandwidth in macOS?  


New Member
Joined: 8 months ago
Posts: 4
May 4, 2018 4:15 pm  

Hi @fr34k. As far as you all have been testing, is there any H2D bandwith improvement with your new script? Just curious.

As it has been already said, thank you very very much for your dedication and hours and hours put into this. +1 to a way of donating! Can't wait to try it! Keep it up!

Soon I will add my system & eGPU details or a build link to this my signature to give context to my posts

Noble Member Admin
Joined: 2 years ago
Posts: 1815
May 4, 2018 4:28 pm  

@aweenz, we've seen:

- a NVME SSD saturates the TB3 22Gbps link in macOS
- a eGPU saturates the TB3 22Gbps link in Windows if specially avoid booting with apple_set_os.efi

The problem appears to be the Mac firmware reserves 10/32 of the 22Gbps link, seemingly for 10Gbps USB 3.1 Gen2 if it detects a eGPU and boot into macOS. So try the strategies in the following thread to bypass Apple firmware seeing a eGPU:

Easiest method would be to *carefully* hotplug the video card into the powered eGPU enclosure while in macOS. If that works, then add a PERST# switch, as described in the above thread,  to make this a more workable solution.

@goalque,  could you create and test a EFI file to be run by rEFInd/USB stick that sets the OS to be Windows instead of macOS (ie: a apple_set_os_windows.efi instead of apple_set_os.efi)? Perhaps that may provide full H2D TB3 bandwidth in macOS?

eGPU Setup 1.35    •    eGPU Port Bandwidth Reference Table    •    Several builds
2015 15" Dell Precision 7510 M1000M + macOS 10.14 & Win10

goalque, fr34k and theitsage liked
Noble Member Admin
Joined: 2 years ago
Posts: 1314
May 4, 2018 6:08 pm  

@nando4 I wouldn't take the risk of guessing other vendor/OS values than hardcoded in the firmware. Most likely other values have no effect.

automate-eGPU EFIapple_set_os.efi
late-2016 13" Macbook Pro nTB + [email protected] (Netstor HL23T) + macOS & Win10
late-2016 13" Macbook Pro nTB + GTX980/[email protected] (Netstor HL23T) + macOS10.13 & Win10

nando4 and theitsage liked
New Member
Joined: 7 months ago
Posts: 3
May 6, 2018 6:57 am  

@fr34k or anyone in the know, is there a way to get a full speed H2D connection on TB3 with this script? I read somewhere here a while back that it was a no with Nvidia cards. Cuda-z screenshot linked below with my current speeds displayed on a UHD LG 27" eM fed by eGPU GTX1080. Thank you!

[/IMG]" target="true">cuda-z

2017 MBP15 3.1GHz, 16GB, Sonnet eGFX650, Akitio Node, GTX1080, RX Vega 64