Installed 16gb ram but only 8gb shows

[thinkxdifferent]

I'm using the gigabyte h170 gaming motherboard. everything works fine, i checked and both the sticks are installed correctly. but both BIOS and windows only shows 8gb. is there some setting i need to change or could it just be a bad stick?

 

[Multipack]

Have you tried one RAM at a time in each slot?

 

[Tradesman1]

What's the model of the DRAM, what CPU and what CPU cooler?