Probably voltage related key is QPI/DRAM (Cpu VTT) and VDIMM memory volt balance. Read http://i4memory.com/ramdetect
and Intel Core i7 920 Overclocking Introduction Guide on X58
as AUTO values isn't optimal.
In sticky threads at http://i4memory.com/f54/
find an approximately bios template format and use that format to fill in your own settings you have tried and post it here so we can see what you have tried