is ddr4 and ddr3 compatible?
DDR4 RAM is not backwards compatible with DDR3 motherboards and vice versa. The notch has been moved to prevent accidental insertion of the wrong type of memory. Instead of 240 pins, each module features 288 pins. ... DDR4 is more efficient that DDR3, consuming up to 40% less power, requiring only 1.2V per module.