I'm having an issue with one of the sticks on my DDR4 kit. The ram is Gskill ripjaws 4 in a 4x4GB kit running at 2133 in an asus x99 deluxe. My UEFI only shows 12GB of ram and only 3 dimm slots populated. However if i run CPU Z it does recognize the forth dimm, sorta.
I've tried to swapping dimm slots to make sure the slot was not bad and I also tried pulling a good stick to see if I had a weird motherboard setting where it would only recognize 12GB of ram but that resulted in me only having 8GB. I also updated my bios. I am out of ideas at this point. My guess is that the dimm is bad