Does the ATI Radeon HD 4870 512 MB work in Mojave on CMP5,1 - Kind of ..!

This post follows up (and is mainly for reference; in case someone else is looking as the solution appears only partially right):

https://discussions.apple.com/thread/250449127?answerId=250858306022

The answer should be kind of...

This is posted mainly because there may be a situation where someone needs to boot a Mojave machine and this is the only one immediately available.

I can confirm that the ATI Radeon HD 4870 has booted Mojave 10.14.4 (from NVMe) bootrom 144.0.0.0 on a machine where Mojave was already been installed.

In my case, I normally run a Vega64, however, recently went to a screen with 2560x1600 resolution requiring a dual link DVI adapter. The adapter that came by post had problems, so needed a way to keep working without all of the flickering.

Without remembering that Mojave has a metal GPU requirement, I pulled the Vega64, and put in the old 4870.

It gave a boot screen, and then loaded Mojave.

I can work on documents, web, and watch youtube. However, it is not detected by Geekbench or VideoProc. So, no one should take this as a solution to provide metal or even OpenCL.

That said, my Dell 3007WFP is working at 2560x1600 24-bit color and looks great working on images in Photoshop and editing large documents. Logic 10.4.8 works. FCPX though doesn't start, stating it requires hardware acceleration lacking in this GPU.

So, the 4870 is getting me by for the weekend, while I await a new Dual-Link DVI to mini DP adapter to arrive.

Here are the screen shots:

Hope this helps, in case someone else should be stuck in a pinch.