Graphical Glitch When Disabling CSM Mode - HD4600 iGPU

Mar 6, 2014
Classic Mac
Mobile Phone
Hi. I'm still a beginner to Hackintosh but I have managed to create a dual-boot setup with Mojave and Windows 10 on my laptop. So far everything seems to be usable but I have a couple of problems I need to address.

When I try to disable CSM mode in the BIOS, I encounter a weird graphical glitch on boot where the Apple logo duplicates itself several times across the screen. Once the system has booted to the lockscreen, the display becomes completely illegible with a horizontal-line pattern that garbles the image.

If I re-enable CSM mode I do not encounter this problem and everything displays as normal. However, I do not like to keep CSM mode enabled because it causes the BIOS and bootloader to display in a very low resolution which looks a total mess each time I start my laptop.

Specs: Intel i7-4720HQ w/ HD4600 iGPU and NVIDIA GTX 970M

I am using Rehabman's HD4600 config in Clover. I have the NVIDIA GPU disabled using nv_disable=1 in the boot arguments.

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