Here's the list of supporting motherboards and the required BIOS upgrade version:
P6X58D Premium (0222) P6TD Deluxe (0209) P6T Deluxe V2 (0704) P6T Deluxe / (1804) P6T SE (0608) P6T (0904) Rampage II Extreme (1639) Rampage II GENE (1033)
P6X58D Premium (0222) P6TD Deluxe (0209) P6T Deluxe V2 (0704) P6T Deluxe / (1804) P6T SE (0608) P6T (0904) Rampage II Extreme (1639) Rampage II GENE (1033)