Guys i’ve read all the similar posts on this issue with gigabyte boards.
I had have this prob (earlier post last year):
"This drive was running fine for months then one day i turned my comp on and the drive was showing up as a 500gb(in the bios) that needed to be formatted. The only way i can get it back to 1500gb is by running gigabytes xpress recovery 2, however this only fixes the problem temporarily as soon as i shutdown my comp it goes back to 500gb. I don’t have another comp to test this drive on. What do i do?"
i found a solution using the helpful prog: Testdisk
testdisk recovered my HDD without any data loss