> Andreas [...] knows the issue with having two Radeon cards
> in a MorphOS system

I knew it wasn't possible to have MorphOS use two Radeon cards, but not that it wasn't possible to have MorphOS use one single Radeon card as soon as another Radeon not supported and not to be used by MorphOS was connected to the board.

> and the limited # of PCI-E lanes (and the slot configuration) of an X5000.

As said by Spectre660, there are adapters from PCIe x1 to PCIe x16, which are just dumb physical adapters with only one lane connected on the x16 side so should be completely transparent to firmware and OS.

> The simplest answer would be that eventually an HD 7750 driver
> will be released for MorphOS.

How will MorphOS cope with an additional Radeon/FireMV/FirePro card put into the PCIe x1 slot for Linux then?