zightbaoe :
I already have 2 4gb modules in. If I were to want to get a single 8 gb could I use it with one of my 4gb sticks for dual channel and the use my remaining stick for a different slot. Then could I dedicate 4gb of ram to my minecraft server and use the rest to help me render my videos and record. Also what would you reccomend for my upgrade that I get for overall system performance. Some more ram, an ssd, or a cpu cooler. (Have a gtx 760 i5 4670k 8gb ram 1tb caviar blue)
You're thinking of each slot being it's own thing such as a hard drive would behave. Let's say you have 4 2GB modules and you plug them in; your computer will recognize that you have 8GB of RAM installed. It won't know how many modules you have installed, just the TOTAL amount of RAM installed.
EDIT: BIOS may know how many modules, but not likely the OS will. But my point stands, your RAM will get added up.
So keep your 2 modules of 4GB RAM where they are (make sure they are in the right slots for dual channel). And yes, you can stick that 1 module 8GB of RAM into an empty slot, most preferably the one closest to the CPU.
May I suggest you buy another module of 8GB RAM so you can dual channel your 8GB of RAM? Or if that's too much, just buy 2 modules of 4GB RAM instead of using a single module of 8GB? There will be a performance increase having two modules vs one.
For the amount of money you will have to drop for any improvements isn't really worth it in your case. You have amazing parts from what I see you have listed. You won't benefit much from an SSD until your PC starts booting more slowly over time, 8GB of RAM is good enough for anything, and 1TB is a lot of storage; so your build is awesome
What CPU cooler do you have installed right now?