Hi,
I recently turned my Mac Pro 1,1 on which has had the GPU upgraded to an MSI 650ti boost (2gb), it used to work and now I get a no signal detected on the monitor, I can VNC the mac and it recognises the GPU and my old GPU still works in the Mac. Noted that I have OS X 10.9.5 installed through macpostfactor. Another note ran Cinebench with my old ATI (521mb) and got 32 fps upgraded it to 650ti and only got 10 fps.
I recently turned my Mac Pro 1,1 on which has had the GPU upgraded to an MSI 650ti boost (2gb), it used to work and now I get a no signal detected on the monitor, I can VNC the mac and it recognises the GPU and my old GPU still works in the Mac. Noted that I have OS X 10.9.5 installed through macpostfactor. Another note ran Cinebench with my old ATI (521mb) and got 32 fps upgraded it to 650ti and only got 10 fps.