You need a 6GB (3x2GB) kit of memory NOT a 4GB(2x2GB) kit. The i7 930 has a "Triple" Channel Memory Controller (Triple as in 3).
Newegg.com - OCZ Gold 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory Model OCZ3G1600LV6GK
Newegg.com - OCZ Gold 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory Model OCZ3G1600LV6GK