hi...
yes win7 x64 did run well ... though some installation issues with a raid card; so normally the board should be ok. but, after a "soft off" the bios doesn't boots correctly and there is no video output. if i pull off the power cord and put it back into the power supply the pc starts correctly. so one out of these two components is defect i guess... however i maybe change the board tomorrow, but first i would like to try exactly your bios settings if this is possible...

or someone else reading haz a asrock x58 extreme?

the hd(0,2) error was with a selfmade bootstick with one gpt partition. i'm still confused what really is necessary and what are the steps to make a good mac-os-install-usb-stick.

but, it seems that the KP has to do with the radeon 4870. netkas.org seems to be the right point of informations about snow leopard and radeon cards, but i'm still not sure what to do. there is a guide which tells me to set -x flag oder -pci0 flag, but still same KP.

so long. thx for staying with me

edit: -x means boot in safe mode. didn't help me woth several versions of empire efi (including legacy 1.085 f.e.)