If you have three displays connected to each graphics card in one of the following configurations: a Mac Pro (Mid 2010) that has either the ATI Radeon HD 5770 or ATI Radeon HD 5870 graphics upgrade kit or two ATI Radeon HD 5770 graphics cards or a Mac Pro (Early 2009) that has a ATI Radeon HD 5870 graphics card ? … one of the following issues may occur: When using a DVI connection, a Mini DisplayPort, and an HDMI connection, the display connected via DVI may turn black. When using a DVI connection and two HDMI displays, the display connected via DVI may turn black. (more…)