SLI not working (or so I assume)

So I noticed I have been getting the same FPS in all my games be it FC3, BF4 or Metro LL with one 770gtx or both of them. In control panel it says SLI enabled but I find that hard to believe. Can some one tell me what's up? 

I have an Asus sabretooth 990fx motherboard and an 8350 fx on it.


edit:

Right, I just installed a program for monitoring and I tried FC3. And I noticed that in FC3 GPU2 had only 10% usage. WHy is that?

Can you tell us what brand and wattage your PSU has?