This is why you dont crossfire in the first place, the performance of two cards is never anywhere near double or even 50% except for some applications or games other then that its a hit and miss situation.
Playclaw can overlay in game the core usages and temps ect of cpu and gpu, also download HWINFO and have it running the the background, it will show current, min, max clocks temps usage everything. Start HWINFO before gaming, play for a while and then inspect the data afterwards.
http://www.hwinfo.com/
Now if crossfire is in fact not working dont expect the gains to be huge at all, id be willing to bet in the perfect situation two 270x crossfire is barely better then a 280x. Best advice is to buy a cheap GPU every second cycle, or buy a expensive one every four.
GL man sorry to be a downer but there are cold realities to PCs and i find many people are reaching and over hyping these things and expecting too much.