Fusion 8 mac beta 2 crashes on startup

Hi guys, I've been trying everything I can think of, but Fusion just refuses to run on my Mac Pro.

While it runs fine on the Mac Pro 4,1 model I tested it on, it won't run on my Mac Pro 1,1 model running the latest Yosemite 10.10.5. I'm using an ATI Radeon 5770 with 1GB VRAM.

All I can see in the system requirements is that I need to be running Yosemite, and I know that my GPU should be fine, since I've run Fusion successfully on weaker older cards on the pc.

Could it be because of the boot loader that let's Yosemite run on this machine? It would be a surprise, since everything else runs fine on it (Resolve and Final Cut X included), but it's worth noting, since everything else on my install is vanilla, no obscure plugins or anything of the sort installed.

Does anyone have any insight? Thanks!

Officially, that GPU is not supported.

To follow up, I just installed an nvidia quadro fx3800 into the mac and tried to launch Fusion and it crashes just like before. It makes me think the reason Fusion is crashing is not graphics card related. This is pretty vanilla install of Yosemite, so it shouldn't be a any kind of software conflict. Final Cut and Resolve both run fine. Does anyone have any idea how I might troubleshoot this?
Thanks!

Not something you want to hear, but that card isn't supported either. Don't know if that's the only issue.

I understand that I'm trying to run this on old unsupported hardware so it may be a fruitless endeavor. But any suggestions would be helpful regardless. Seems odd that Fusion is only app I've tried that refuses to run at all. Not a knock against Fusion, as I think Fusion rocks, but it makes me wonder what Fusion is checking for at launch that other apps aren't bothered by. Is Fusion doing some kind of strange license check on the hard drive (remember I have a modified boot.efi)? Is it looking for specifically supported gfx cards and if it doesn't find them it crashes?

Fusion require SSE 4.1 compliant CPU.