I have Mac Pro early 2008. It came originally with ATI Radeon HD 2600 XT graphic card. I found on the Apple support website that ATI Radeon HD 4870 was offered as an upgrade card for my computer. My only issue is what can I do if my computer doesn't recognize the HD 4870 card automatically? My old graphic card is dead. I won't be able to instal the drivers manually for the new card since I have no display on the monitor at all. Any hints? Thanks.