Hello Guys , First of all, I have this 2x 4gb RAM s which are on my M/B , MB is : Z77a-G43 , my MB also has two additional slots ( black slots ) which i think are for the RAM as well , i want to buy 2x4 more 4GB rams to add there , can you suggest which one to buy ? should it be like pair? because last time when i put my RAMs in Black slots instead of Blue one, they didn't work, little bit noobie in that aspect so i need help with it
https://imgur.com/a/eEg1W
https://imgur.com/a/eEg1W