This 8GB RAM is 100% compatible with the Gigabyte GA-B85M-HD3G. Help in selecting the right RAM: We offer you faster 1600MHz RAM for your system. Due to the backward compatibility of our RAM to 1333MHz, you can also mix these with existing 1333MHz modules. RAM with ECC provides higher security through error detection and correction. The ECC function is supported if all existing memory is equipped with ECC. You should use UDIMM ECC RAM if existing modules are ECC-equipped. Using different RAM sizes in the slots is possible. Dual Channel Mode is also supported by Intel Flex Memory Technology. When using different RAM capacities, ensure that the memory in memory channel A is larger than the memory in memory channel B.