I fail to see how any os4 capable computer would not be a botleneck . And what Amiga application would take advantage of a RX based card? Most advanced games we have Are from the late 90s . Not to mention our dogslow chipsets and lack og multithread support
Current hardware doesn't really take full advantage of any of the high end video cards from the 6750 up.
So what?
If I had the choice of a Radeon HD 7750, and R7 250, or an RX580, I'd prefer the RX580. For one thing, it's a current card.
And if we aim lower, say an RX550, it shouldn't be too cpu limited.
That said, since I'm a MorphOS user, and I haven't bought an X5000/20 because I'm hoping for an X5000/40, if I had one I'd probably drop down to something like an HD 4770. I'd get a driver with overlay support and and video card that's reasonably suited the cpu's capabilities.
I've used a 7750, it's not that much more impressive. And the R7 250 kind if a dog, slower than my R7 260X, which in turn can't touch an HD7850.
What I'm hoping for is R600 (or possibly R700) AGP support for our legacy systems, and 3D acceleration for all the new Radeon HD cards that have been added to the support list.
All that being said, I still think what Hans de Ruiter has accomplished under OS4 in terms of video card support is remarkable.
Pity there isn't someone with that level of talent writing network and sound drivers. You might have those dreadful P1022 based boards in your hands if those issues were resolved.