Hi all, I use a Mac Pro 3,1 / early 2008 with a 'PC' card (MSi Twin Frozr III, 2 GB) so I can use it with the large desktop of a 40" Philips BDM4065 '4K' / UHD monitor at 3840x2160. It began restarting spontaneously a few weeks ago. After that, this happend more and more often, up to half a dozen times a times a day, often in small series. So I de-attached the SSD and internal backup HD and replaced a set of 3 HD software RAID set I used before the SSD, to test if it was the software. It still restarted by itself.. so it must be the hardware. I checked the LEDs next to the RAM risers. Only thing abnormal is the 7th LED not lighting up, meaning that the EFI doesn't recognize the graphics card. Since it's a non-flashed PC video card, this is to be expected. Still, since I put in the 'official Apple Mac' NVIDIA GeForce 8800 GT, the machine hasn't restarted by itself. Not once in two days now. Therefore my question is: Can a bad video card be the reason this Mac suffers from spontaneously restarts?