1.What is wrong?
2.Are there any necessary drivers i have left out
3.Is the single memory stick( I plan to extend it to 16 GB when i have the money) or any other part like the motherboard creating a problem?
I'm not entirely sure, but it's possible it's RAM issue. RAM running in single-channel is a lot slower than dual-channel. Also, at what speed is the PCI-e port that has your 7870 running at? It could be a bandwidth problem. What is your power supply?