I'm am sick of being on the **** end of Apple's pricing stick (I live in Australia) and have decided to buy a PC 4870 and flash the ROM. I can get a good deal on two 512MB cards, and I thought that would be awesome for gaming. My questions are; 1- Will the cards work properly in Mac OS X if I crossfire them? 2- Do both cards have to be flashed to Mac versions? 3- Is this possible at all?