X58 Chipset Your mobo utilizes the X58 chipset architecture [Core i7, X58, Socket LGA 1366 (1366 pins)] Memory configurations vary from board to board and it seems that Dell has varied its design. Don't know what you are attempting but the i7 920 features a clock locked at a maximum of 1066. To what extent you can mix and match sticks is a matter of digging further regarding your specific mobo design. Look at the ASUS P6T and the Rampage II which use the X58 chipset. Monk