My original HD4870 display card in MacPro 1,1 just died. I am running OS X El Capitan with Pike bootloader. I still want to try last effort in order to see if I can repair it. After trying a PC card of AMD R2 230, the diagnostic LED "CPUB" on motherboard will light up. But I am sure the two CPU are all fine. Then I tried my old X1900, it can boot but the screen is always in low resolution. PC version of AMD 7950 is still very expensive. With the same price, I can get AMD 460/470/480. Does anyone know if new these 460/470/480 card work in MacPro 1,1?