eGPU not showing up in device manager after Big Sur update
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eGPU not showing up in device manager after Big Sur update  


Benjamin Gerber
New Member
Joined: 8 months ago

Hey everyone,

I've been a lurker here for a few brief stretches, almost always when trying to sort out a bootcamp/eGPU related issue. I have recently run into a new problem that I would be ecstatic if someone were to point me in the right direction.

I have recently started using the Mantiz MZ-03 with a 16” MacBook Pro 2019. I have been using it exclusively with windows 10 bootcamp (which I know is not officially supported by Mantiz) and it has worked beautifully with a Nvidia gtx 1660 super graphics card. For the record, the Mantiz MZ-03 was plug and play with windows bootcamp originally. It only required that I connect via TB3 and turn on the MZ-03 when windows was fully booted up—and after a windows chime sound, the Nvidia card was detected immediately and performed as expected.
Unfortunately, I have recently run into an issue to where my MZ-03 and Nvidia card are not detected by windows. When I boot into windows 10 and turn on the MZ-03 I hear a windows chime sound (external device connected sound) quickly followed by a windows chime (external device disconnected sound). The Nvidia card no longer shows up in device manager, at any point.
I am not an expert in eGPU set ups, but the most likely reason for this change in behavior is due to recently updating my MacBook from OS X Catalina, to OS X Big Sur. From the reading I have done on this website it seems like there was a firmware update that came with the Big Sur update that may be causing this issue. So far, I have downgraded to OS X Catalina and still have the same detection issue, which further implies that the firmware is to blame.  According to Apple support, it isn’t possible to revert the firmware to its "pre-Big Sur" state (although with a little poking around on the internet, I do believe it is possible, but not a preferable solution). 
My questions are: Am I right to suspect the Big Sur firmware update is the issue? Or is it possible that a Windows update at some point screwed things up? I believe I am running the 1904+ windows 10 build, maybe it's worth reverting to a previous windows build, or reinstalling in general just to rule it out. My detection issue did seem to line up perfectly with the Big Sur update, but maybe thats a coincidence. What do you guys think?
Again Quick summary:
MacBook Pro 16", 2019
6-Core Intel Core i7
AMD Radeon Pro 5300M -internal graphics card
Nvidia GTX 1660 Super - external graphics card
Mantiz MZ-03 Saturn Pro II- eGPU enclosure
Windows 10 Educational (Build 1904 I believe.  I will double check once I boot back into Windows)
If you would like more info, let me know. And thanks to anyone who reads this! Any help would be great.

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