My mobo is the X299 Aorus Gaming 7 Pro, my processor is the i9-10920X, and my memory is G.Skill Flare X.
In failing to find SSDT and DSDT help (and the fact Titan Ridge is another headache for High Sierra running Hack iMac Pro) I took my Windows 7 installation reserved for Premiere and migrated it to X299.
Knowing the USB 3.0 chipset ports don’t work on 7 OOTB, I used a PS/2 mouse. It worked. I was able to navigate installers using a PS/2 mouse to get the chipset drivers and USB 3.0 drivers installed. This in the very least works on X299. Hopefully if it’s a supported SuperIO chip it will also work on Ryzen.
Once the USB 3.0 drivers were installed, USB mice and keyboards work again and I proceeded to install the rest of the drivers:
Success:
Intel Chipset Driver (from Gigabyte)
Intel USB 3.0 XHCI driver (from Techspot/Hardware Unboxed)
ASMedia ASM3142 driver (from Startech)
Nvidia drivers (pre-installed, Windows managed to re-install properly after INF updates)
Intel RST driver (from Gigabyte)
Hotfix for RST (from Gigabyte)
Realtek Audio (from Gigabyte, since Realtek themselves have pulled HD audio driver installation from their official site)
Intel i219-V Ethernet (from Intel)
Intel Management Engine (HECI)
Not tried:
Atheros Killer NIC E2500 (Not using it, Killer Networks stuff increases DPC Latency)
Atheros Killer WiFi 1535 (swapped it out for a AX200 due to same DPC Latency concerns)
Performance counters for DDRIO (8086:2088) (Dell apparently offers an INF update that fixes this, but haven’t tried it because the utility was targeted for Win10)
Unsuccessful:
Intel AX200 M.2 WiFi (Windows 10 exclusive)
Gigabyte Titan Ridge card (Windows 10 exclusive)
Digressing:
Latest HWinfo64 installed fine and correctly identified the processor as a 10920X.
Windows Experience Index crashed at the memory test because 24 cores is too many cores.
Nvidia Control Panel’s 3D preview is broken.
But the big one:
NONE OF THE ADOBE APPS WORK.
TL;DR: Having a PS/2 mouse and keyboard helps you get the USB 3.0 drivers onto your Windows 7 installation much easier. It’s only boards with no PS/2 ports that require something like a 2 machine + Task Scheduler silent installation.
So, gonna assume the AX200, Titan Ridge and Adobe CC are impossible to run on Windows 7.
Why did I do this? Because this was easier to setup than High Sierra with extensive DSDT and SSDT modifications. Unfortunately with the Adobe apps not working, it means I have to go High Sierra.
This was done on a spare installation so none of my mission critical work got destroyed, but learning this means I am screwed.
The Dell INF is here if you’re interested in running Cascade Lake-X with all the INF entries updated properly: https://www.dell.com/support/article/en-us/sln317623/errors-displayed-in-windows-10-windows-device-manager-after-a-intel-cascade-lake-processor-upgrade-on-precision-7820-7920-workstations