Use all memory slots or not?

Should I use 4 X 4G or 2 X 8G on my mother board. Should I fill all 4 slots or just use 2? Does either way have any benefits? I will not be upgrading to 32G.




2 slots is generally more reliable from my experience, but I'm also pretty sure it's more expensive, so it doesn't make a huge difference.

Using just two modules is supposed to be better for overclocking too, so if you're trying to get the most out of your cpu, then it's usually better to only populate two slots. Although, it probably won't make a huge difference, if any. 

i believe most manufacturers recommend over

and i think that if you use a 32bit os it sometimes won't recognize or use the extra 2 slots. (but don't quote me on that)


I am going to install Windows 7 64 bit.

edit: I installed 8.1 64 bit.


I think I will go with 2 X 8, less parts to go wrong.  Thanks