Ok, so ive been looking around, trying to learn and understand the way that ram works. Ive gotten one answer that said
"The addressing is best for 2 sticks, and when you use 4; it slows down"

Another answer said something like:
Theres bank/channel interleave that makes the memory read like one stick
Also I read something about the memory density also being a factor.

I dug further and found out that theres a higher speed limit on my board for 2 sticks vs 4, so now im trying to put an image in my head of how and why, and... pfft.

Can anyone explain, or recommend a resource that would answer these questions?