Hello, I have a problem with the installation of a 4870 1go with a 4870 512. In the panel of control all is activated well, but there is a yellow lozenge indicating a message like what the Crossfire is different but activated. When I throw a game, I have a total stop of the machine with cut of the immediate food. This food of Advance mark makes 750 watts, 4 lines, the transistors are of good quality. I have a motherboard Asus P5Q pro, a Quad 9550, screen 26 '', this for the basis of my material. Would I like to know therefore why I have a total stop, to see a plantage and reason even in Crossfire X, with the 2 cards it doesn't function? the 2 cards are Power Color. I thank you for your answers.