[GUIDE] DSDT override eGPU error 12 fix
Considering Step 2; [In Memory Substitution] I have Grub preinstalled and use it to load Windows/Manjaro... To get this to work, I would need to;
A) Replace Grub with Clover
B) Add a Clover boot entry onto Grub...
I have no idea how to go along with replacing Grub with Clover,
however, if I did go route B),
I would need to place another Fat32 partition to place Clover, yes?
C) Add a Grub boot entry to Clover?
You can have multiple boot loaders in the same Fat32 partition or EFI partition. A separate disk per boot loader is necessary only if you want them all to show up in the Mac's Startup Manager (hold option at startup).
In the EFI partition, the EFI/Boot folder contains the default boot loader named bootx64.efi. This is usually a copy of a boot loader .efi file in another folder in the EFI folder of the EFI partition. "Microsoft" for Windows, "Ubuntu" for Ubuntu's grub, maybe you have a "Manjaro" folder for Manjaro's grub? "Clover" for Clover.
Installing an OS (linux or Windows or Clover) adds the OS specific folder to the EFI folder and usually replaces the bootx64.efi file with a copy of the boot loader for the OS.
Mac's Startup Manager only boots bootx64.efi in EFI/BOOT folders (as well as MacOS boot loaders in certain locations). It can also boot legacy OS's (usually named "Windows" even if the legacy OS is something else) for disks containing boot code in the MBR and a fdisk or hybrid fdisk/gpt partition table.
Clover and grub can be configured to allow booting any efi file in any folder.
More info on boot files at:
I was able to get my e-GPU working today patching DSDT. Thanks for the great info!!
I am curious I have the mantis venus. It has a card with USB and SATA in addition to the GPU inside. After the patch I can now use the E-GPU. However under windows I cant access the USB or SATA. Do I need another patch to make them work under windows? They work under mac os just fine.
Just a warning I applied Windows Update KB4512941 and all of a sudden my egpu card was no longer loading into large memory and had error 12 again even with the dsdt.
I tried every trick listed here.. reinstalling the graphics card and cleaning, tried every port, booted to selection screen before plugging in, disabled the pci bridge, uninstalled the PCI bridge, set that bcdedit option for PCI, NOTHING worked. Restored back to before the update and all is fine again.
Also found that uninstalling the update fixed the issue and my egpu loaded into large memory again (system restore is not necessary). Might want to disable updates until the next feature release.
Hi everyone, I have read through all the posts in this forum and still cannot understand exactly how to fix my error 12. Is there an easier step by step guide anywhere or automated process? My setup is MacBook Pro Retina mid 2015 15" with R9 m370x bootcamp Windows 10 using eGPU Core X with Radeon 5700. I am able to install the modded drivers but I get the Error 12 ("
As per opening post:
I’m struggling to find an alternate solution to the testing mode work around.
I am able to use clover and successfully make changes in windows that results in a working egpu. My only problem is. I’m unable to customize the boot options within clover. I have three extra boot options. The refind bootloader works fantastically as a replacement. However... I can’t use the vga workaround. The script thats out there doesn’t work? I’m not exactly sure how its supposed to launch windows based on the entries provided.
I did try to combine refind with clover, but every time I boot into Windows, I get an error and the system overwrites my efi partition bootx64.efi file and prevents refind from booting again.
Any ideas? I’d use clover, but I don’t see a way to customize boot entries like with refind.
Never mind. I was able to set clover to default to booting windows with the necessary DSDT changes. I'm essentially using refined as my boot loader and chain loading windows with clover. Works pretty well now that I've sorted out the weird clover config issues.
Unfortunatley I hit a block at the 'Update Feb-2019 >>' step. I followed the link but the command will not run. Bash is not recognised on my system ( Mac Pro 2013 / Win 10 pro).
Any idea why this step is a dead-end?
@jcp-123 If you’re trying to set up an eGPU on the 2013 Mac Pro, @nando4 has already compiled a DSDT file for it. Also of interest is this discussion about recent firmware change allowing the Thunderbolt eGPU to be detected in Windows on this machine.
I used the alternate method to find and fix the errors in the DST file - compiled without error. My issue is getting to the next stage which is to load it. Very new at this!