HD630 Underperforming in macOS Mojave

My Hackintosh is running smooth for the most part, though something is wrong with my graphics. Whenever I have a GPU-"intensive" program open, the rest of the system becomes very slow.

I'm running SMBIOS of a Macmini8,1, and my Devices properties are as follows:

I don't have any graphics injected from the "Graphics" tab. I'm rocking an 8400 with an ASRock Z370 ITX/ac.

Kexts installed are AirportBrcmFixup, AppleALC, BrcmBluetoothInjector, BrcmFirmwareData, BrcmPatchRAM2, IntelMausiEthernet, Lilu, SMCProcessor, SMCSuperIO, USBInjectAll, VirtualSMC, and WhateverGreen.

Thank you! :)