Computer Stuttering, Need Help

[KerbalPhysicist]

   Hi I know that this probably isn't in the right place, but I didn't know where to put it.

My computer has been stuttering for no apparent reason. And I mean seriously stuttering. The Audio and video both freeze/lag for no apparent reason. It starts about 15 minutes after I start the computer.

I have Checked and it is ​definitely not a temperature issue.  It started when I was running on integrated graphics, and I suspected that this was the problem, but then I put in A nice high class video card, and it did nothing to fix the problem. I am running on a more than adequate power supply. I have also even gone so far as to try re installing Windows. I am already saving up money to replace the MOBO/CPU with an AM3+ and a FX6300, because I am assuming that the motherboard or the processor is the problem. I would really appreciate it if you had any tips.

Thanks,

Sam

 

Edit: Oh And I forgot to add that I have used the resource monitor + task manager + my graphics card monitor to tell me that I have never even hit 50% of my system's full power!