Incompatible RAM modules (PC Building Simulator)

What in the game in one system, you cannot install two identical RAM strips of different sizes? The computer came with two feet of RAM. Should be increased to eight. I have one dukhigov. Cheaper to buy one on four than two? But no, you need four or two or two by four! In reality, planks of different sizes, ceteris paribus perfectly work together! Kalita me, it's incredible!
PS. And this omega systems are all shit, even the icons on the desktop to drag and drop impossible. And so the game - incredible zalyalova, did not notice that six hours have flown by.