I know this post is a bit long in the tooth but I am having exactly the same issue. With 32gb of ram only 16gb is usable and with 16gb only 8gb is useable.
I've tried most of the things mentioned in the thread except flashing the bios which doesn't appear to work.
My memory, Corsair cmv16GX3M2A1333C9 isn't on the Gigabyte compatability list but it is 1333mhz and I see people who do have listed memory are also having the problem.
It looks to me like this is an issue for Gigabyte to solve.
Has anyone contacted them or found a solution?
