Hey, I bought second ATI Radeon 5770 GPU for my MP today. Problem is that I can't get both of them running at the same time. GPU I bought today is non-Apple GPU but another 5770 is original GPU for MP. Both of them works just fine when I use just one of them but if I try to use both of them at the same time, then monitor that is connected to non-Apple GPU doesn't show a picture. I can see that monitor in settings though but screen stays black. In settings non-Apple GPU is shown as "ATY,Hoolock, 1024 Mb" when both GPUs are installed but when I use just that "non-Apple GPU" it is shown as 'ATI Radeon HD 5000, 1024 Mt' Computer is Mac Pro 5.1 and OS is macOS 11.13.4. I use PCIe slots 1&2 for GPUs. Anyone knows what is the problem and how could I fix it? Or is it even possible to fix?