The bios update might be mandatory here. If you download the bios for the right version of the motherboard you have should you have no worries. Mention this because Gigabyte sometimes has more revisions of the same motherboard.
Just put the
unpacked bios file on an empty usb stick (fat32) and look for the update tool in the bios,follow the steps. Don't interrupt until finished!
Also might need to raise the voltage for the memory controller,
comes from the next article,
DDR DRAM FAQs And Troubleshooting Guide
may have some other things to try in it.