What gives? A search of Google and the Gigabyte site turns up no useful reference to the GA-8IGXP except for Tom's Hardware, only the GA-8IGX or GA-8IEXP. Would like to find one for the DDR333 support.
This question has been asked before and short answer seems to be that the 81GXP was a protype and will not be released to the general public anytime soon. However this does not stop them from releasing one in the future. Use the "Search Boards" option to look up those discussions. Good luck!