Okay, i've had this problem for around a year now. I never used to game much on my PC as I had a Xbox 360, I make gaming videos on YouTube and my card used to work fine. About a year back I had an issue on my Radeon HD 6850 with any game I play. I assumed it was a problem with the hardware in the card because it was just out of warranty, I didn't use it much so I left it for a year. About 2-3 weeks ago my new Sapphire HD 7970 Ghz edition arrived, I also sold my Xbox 360 thinking I would switch to PC gaming.
Anyway, the problem persisted, the problem in its best way of describing it, is I can be doing anything in a game, running through a huge battle in Crysis 3, or staring at a wall on ArmA and my frame rate will go from 70+ down to anything from 5-15 fps.
Obviously I can now rule out my 7970 as it is brand new, I can also rule out my HDD (formatted yesterday along with a clean install of windows), it is NOT a driver issue, as it is a continuation of a problem I've had for around a years worth of drivers. It is NOT my system overheating as everything is running at around 30 degrees. My GPU raises to 50-55 degrees when under load. My processor which is clocked at 3.3Ghz goes to around 40 degrees under 100% load.
(Everything run's nice and cool because of my NZXT Phantom Case

)
So, what is the issue? My friend reported to me that my voice whilst on skype wen't 'stuttery' or 'laggy' whilst I was experiencing a lag spike.My microphone is plugged directly into my motherboard through USB 2.0 which has lead me to believe that because my motherboard didn't quite reach the screw-holes in my case so we had to bend it a little (bad I know and it wasn't anything major, more just putting pressure on it so it would fit) but could this have affected my system just a minimal amount in such a way that it could possibly cause the intermittent, absolutely random FPS drops?
My system is 64bit if anyone was wondering and I have 12gb of DDR3 RAM installed clocked at 1333mhz. My processor is the AMD Phenom II X6 1100T Black Edition. I think that is all the information you need

if any of you know a tool where I can simply paste my specs in it would be easier but I think it's all there, if not then let me know
Any help?!?!
My main question is, could the motherboard be causing this? if yes, it's on its way out!