2018 Mac Mini [8th,6C,B] + RX 6800 XT @ 32Gbps-TB3 (Mantiz Saturn Pro) + macOS 1...
 
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2018 Mac Mini [8th,6C,B] + RX 6800 XT @ 32Gbps-TB3 (Mantiz Saturn Pro) + macOS 11.5 & Win10 21H1 [itsage]  

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itsage
(@itsage)
Founder Admin
Joined: 5 years ago
 

Like many Mac users, I've been waiting for Big Navi support for a while. It doesn't help that card availability and pricing are insane for the past year. You know it's really bad when a graphics card priced at twice the MSRP and sold out immediately.

I got to my local Micro Center store prior to opening time and there were at least a dozen people ahead of me. They had enough inventory so I was able to get an ASRock RX 6800 XT Taichi [unboxing]. Not too many AIB graphics cards provide USB-C monitor output so this was my main priority in selecting a GPU.

 

System specs:

Late 2018 Mac mini – i5-8500B/UHD Graphics 630 iGPU/32GB RAM/256GB SSD

 

eGPU hardware:

Mantiz Saturn Pro + RX 6800 XT + 2m Thunderbolt 3 cable + HP Z38c 38" QHD+ ultrawide monitor

 

Hardware pictures:

 

Installation steps:

My primary desk setup for this 2018 Mac mini uses an ASUS portable USB-C monitor for boot screen through USB-C port. This time I tried with a different desk that has an HP Z38c QHD+ ultrawide monitor. This 38" monitor has USB-C port that hosts mouse, keyboard, and the occasional webcam through USB-A expansion port. 

In macOS 11.5 Beta [20G5023d], RX 6800 XT eGPU works plug-and-play. The RX 6800 XT can power the Z38c through either DisplayPort or USB-C. One nice feature of this monitor is that it sets the other connected monitor inputs to INACTIVE. This is very useful in macOS when I boot up through USB-C input via the Intel UHD 630 then switch over to DisplayPort input through RX 6800 XT

In Windows 10 Boot Camp, I wanted to test with newer version than 1903 V1. My 2018 Mac mini is currently running a Dev build of 21H1. The setup procedure is summarized below:

  • Boot into Recovery mode to disable SIP through Terminal. Open Startup Security Utility to set Secure Boot to No Security and External Boot to Allow booting from external media [in Recovery]
  • Download and install Windows 10 ISO through Bootcamp Assistant [in macOS]
  • Run DDU with Admin privileges to disable Windows auto-installation of drivers [in Windows]
  • Hot-plug eGPU to Thunderbolt 3 port #1 closest to the Ethernet port [in Windows]
  • Confirm a new Microsoft Basic Display Adapter in Device Manager then install Radeon drivers [in Windows]
  • Restart the system with eGPU connected [in Windows]

If you don't use an EFI boot loader, the iGPU connected monitor output will go blank shortly after the Windows logo. For Apple T2 Macs such as this 2018 Mac mini, I use the modified apple_set_os.efi v0.5 to keep the iGPU activated through eGPU cold boot. Once confirmed the Radeon eGPU is working is Windows, I switched over the eGPU-connected display/monitor input to get the best performance.

 

Benchmarks:

For about a year, eGPU performance with Radeon drivers was very inconsistent. I would recommend installing either 20.4.2 and older or 21.3.1 and newer for good eGPU performance. I didn't have time to test any games in Boot Camp, but wanted to run Luxmark and Unigine in both macOS and Windows to see macOS driver progress for Nav21 graphics cards.

 

macOS 11.5 Windows 10 21H1

 

Comments:

This Taichi RX 6800 XT performs very well even in Quiet BIOS during these test. It's very quiet during the entire 2 hours. With that said it's far from being worth $1,269. Unless you can manage to buy the reference cards at MSRP, don't buy in this market. 

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2021 13" ASUS ROG Flow X13 (RTX3050Ti) [R5K,8C,H] + RTX 3080 @ 64Gbps-XG (XG Mobile) + Win10 20H2 [build link]  


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Susurs
(@susurs)
Estimable Member
Joined: 11 months ago
 

Thank you!

Are there some changes going from 20H2 to 22H1 with regards to eGPU? Is the latest feature version still safe and ‘eGPU friendly’ in the ame way as previous?

This post was modified 5 months ago

|| Mac mini 2018, i7, 32GB || macOS 10.15.7 || Bootcamp W10 20H2 || Sonnet Puck RX 5700 eGPU ||


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itsage
(@itsage)
Founder Admin
Joined: 5 years ago
 

@susurs, I can't tell what changes Microsoft made. As far as Boot Camp eGPU on the Mac mini, it's the same procedure for me between 20H2 and 21H1.

 

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external graphics card builds
best laptops for external GPU
eGPU enclosure buyer's guide

 
2021 13" ASUS ROG Flow X13 (RTX3050Ti) [R5K,8C,H] + RTX 3080 @ 64Gbps-XG (XG Mobile) + Win10 20H2 [build link]  


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pavel
(@pavel)
Active Member
Joined: 4 months ago
 

Good day. Works on macOS 11.4?

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

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itsage
(@itsage)
Founder Admin
Joined: 5 years ago
 

@pavel, Yes, it should work the same as 11.5 beta in this build.

 

LinkedIn | Twitter | Facebook | Youtube | Instagram
 
external graphics card builds
best laptops for external GPU
eGPU enclosure buyer's guide

 
2021 13" ASUS ROG Flow X13 (RTX3050Ti) [R5K,8C,H] + RTX 3080 @ 64Gbps-XG (XG Mobile) + Win10 20H2 [build link]  


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pavel
(@pavel)
Active Member
Joined: 4 months ago
 

@itsage, Where did you buy the Mantiz?

 

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

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