One test I wanted to run was the performance difference between display loopback mode through the same Thunderbolt 3 controller as the eGPU vs separate TB3 controller. The 2018 Mac mini with its two TB3 controllers and four ports was the perfect candidate for this experiment. I used a Mini eGFX prototype bought on eBay that came with a TUL GTX 1060 3GB. The monitor was an ASUS MB16AC, connected to the Mac mini directly through a USB-C cable.
Late 2018 Mac mini – i5-8500B/UHD Graphics 630 iGPU/8GB RAM/256GB SSD
ASUS MB16AC portable USB-C monitor drew power directly from the Mac mini's USB-C port. Intel UHD Graphics 630 iGPU ran the USB-C monitor while GTX 1060 eGPU's ports were vacant except for one DisplayPort during the external monitor mode testing.
In macOS I could see the enclosure under System Information > Thunderbolt tree and all devices through the TB3 enclosure in PCI tree. Due to no Nvidia web drivers in Mojave I only tested this GTX 1060 eGPU in Windows 10.
To keep the Intel UHD Graphics 630 iGPU activated in Boot Camp I relied on @goalque's eGPU EFI Boot Manager. These are the basic steps I took to get this setup going:
- Install Windows 10 ISO through Bootcamp Assistant [in macOS]
- Download and copy automate-eGPU EFI to a 24MB FAT partition [in macOS]
- Shutdown Mac mini then connected GTX 1060 eGPU [system OFF]
- Hold OPTION at boot to select EFI boot volume then hit Q to access automate-eGPU EFI [boot selection]
- Download and install the latest Nvidia drivers [in Windows]
- Restart Mac mini then boot into Windows using automate-eGPU EFI [boot selection]
This setup and boot-up procedure allows me to run internal display mode through Nvidia Optimus. Intel iGPU can power any monitor connected directly to the Mac mini (HDMI, USB-C, and Thunderbolt 3) and get loopback acceleration from the eGPU.
Right off the bat AIDA64 showed a clear bandwidth difference with USB-C monitor and eGPU sharing the same TB3 controller vs using separate controller. Loopback same controller is far left. Loopback separate controller is in the middle. External monitor mode is far right.
|Mac mini + GTX 1060 eGPU||Loopback Same TB3 Controller||Loopback Separate TB3 Controller||External Monitor Mode|
|3DMark Time Spy||3,561||3,553||3,586|
|3DMark Fire Strike||9,898||9,936||10,481|
|Tomb Raider 2013||80.3 FPS||81.1 FPS||87.3 FPS|
|Dirt Rally||66.5 FPS||60.5 FPS||80.5 FPS|
|Shadow of Mordor||59.4 FPS||60.8 FPS||65.8 FPS|
|Hitman||67.0 FPS||68.8 FPS||76.8 FPS|
|Strange Brigade||58.0 FPS||60.0 FPS||60.0 FPS|
|Grand Theft Auto V||42.3 FPS||42.9 FPS||45.3 FPS|
These benchmark results indicate there's an advantage in connecting the monitor and eGPU to separate controllers. I will run this same test on a more powerful eGPU.
Would be interesting to see test results for GPU in normal PCIe set up... looks like loop back performance degradation is nowhere near as bad as I thought, but defo be interesting to see if the gap widens on more powerful GPUs.
2017 13" MacBook Pro Touch Bar
GTX1060 + AKiTiO Thunder3 + Win10
GTX1070 + Sonnet Breakaway Box + Win10
GTX1070 + Razer Core V1 + Win10
Vega 56 + Razer Core V1 + macOS + Win10
Vega 56 + Mantiz Venus + macOS + W10
@itsage, The W10 build for Nvidia eGPUs is not as important as for AMD ones right?
I am planning to put my old KFA2 enclosure to use with W10 but I cannot even start it without eGPU, it must be corrupted.
I tried to reset the installation through a safe mode boot but I had no luck, and was planning to reinstall W10. Do I need to delete and recreate the partition with Bootcamp assistant?
@jangoloti_1, Nvidia eGPUs don't tend to have issues with different Windows 10 versions. If your Boot Camp volume is corrupted, it's best to start fresh with Boot Camp Assistant.
@itsage, thanks that is what I am trying since yesterday. I cannot install any build, it gets blocked when installing the drivers seemingly. I am looking for solutions in different websites. Not even linked to the eGPU.
@jangoloti_1, Is it a detection issue of the eGPU in Windows? Do you see it in Device Manager? Run DDU to remove all graphics drivers and PCIe port associations then hot-plug the KFA2 SNPR to see if that makes a difference.
@itsage, It is before that, I cannot even install W10. I deleted my old Bootcamp partition and started anew. It gets to a point where the devices are being detected and then the screen goes black and the Mac is unresponsive. I have tried to do a reset in safe mode thru command line but it does not find the boot file or something. It is as it did not finish installing.
@jangoloti_1, Ok. It may be something else with the Mac mini firmware. Do you have the Security Boot settings disabled? I still have Win10 1903 V1 ISO on my 2018 Mac mini and have not upgrade that to anything newer.
I do have Full security enabled but normally the use of Bootcamp bypasses that security, doesn't it?
I have tried everything but it gets stuck with no HDMI signal after a Windows window logo and a whirlwind, at times it starts configuring devices and then gets stuck.
- Resetting NVRAM (I get a message "Error clearing firmware variables: (iokit/common) not permitted" while doing it on Terminal through nvram -c, with a key combination nothing happens. Can that be it?)
- Repairing disk in Recovery mode.
- With two different iso packages, 1903 and 1909.
- Removing anything connected to the Mac except mouse, keyboard and screen through HDMI.
- Updating to 10.15.4 incremental update.
I really do not know what more to do.
I now this is not the place for this but if anybody has an idea I will not complain...
@jangoloti_1, I'm running 10.15.5 Beta on my 2018 Mac mini and have Secure Boot disabled since the first week of owning it. The Apple T2 Security Chip controls many internal components so when there's a firmware issue, it may interfere with Windows installation. I'd say to try the 10.15.5 Beta and see if that helps.