Hi, I apologize in advance if this has already been resolved, but I've been reading through the original 4870 thread and haven't been able to find an answer to my problem. So here it goes: My system: MacPro 2006 1,1. 16GB. Snow Leopard 10.6.2 Monitor: Samsung SyncMaster 206BW Card I'm dealing with: XFX HD 4870 -- the ZWFC model (1GB) The original story: --------------------- If I tried booting into OS X with both the 4870 and the stock nvidia 7300 (to flash from os x) I would get a kernel panic. So, I ended up booting into DOS and using atiflash 3.7.9 to flash the card to the bios supplied by Cindori in his ROMS folder (ROMS/4870/XFX ZWFL & ZWFC/mac modified.rom) The current status: ---------------------- 1. After flashing, the card boots into OS X just fine. I do get the "power cable not connected..." warning, after the desktop is done loading though. I thought this only affected the ZWFL (I have ZWFC) but am I wrong? 2. This is the one thing I would consider an issue: Now, the card will barely run in Windows XP. I tried it both in my mac pro and on a regular Dell PC, both with WinXP and DOS. Basically the card glitches like crazy and you can barely see the image. Since the card now at least runs in os x, I also tried reflashing with the same Cindori file but this time through his os x flash utility. Same deal. The card works on os x but glitches on windows/dos. As far as I read, the mac netlists for the card basically leave the dos bios intact and just add the EFI support but I guess this might not be the case. So, any thoughts on the above? Should I be using a different file to flash? Again, if someone already figured this out then I'm sorry for reposting. Thanks! I'm attaching the os x info for the card. I can also provide my card's original bios and the one I flashed to.