GPU Throttling?

[Infernofight]

Hello,

 

Okay so I've noticed this every now and then. Sometimes when I am playing a game, I noticed my video card is at a lower frequency. When things are fine, its usually at 1245 Mhz and stays there while gaming and my fps are great. I was playing minecraft today and also noticed this with Burnout: Paradise that sometimes the frequency stays low and constantly is going back and forth between about 810 Mhz and 1045 Mhz, it almost looks like thermal throttling but the GPU is only at 45 degrees Celsius. Then I notice the power consumption is only at 36% and the GPU usage is all over the place. What could be causing this? I'm not doing any other intensive tasks while gaming and there is no AV scans going on or anything. I've included a picture of some graphs from msi afterburner; Pay attention to the GPU usage and Core Clock. When this happens it causes low fps and stuttering in game.

 

Specs:

OS: Windows 7

CPU: AMD FX-6300

GPU: GTX 760

Mobo: Asus M5A97 R2.0

RAM: 8 GB 

[Cactu]

What is your psu

[Bouzoo]

Dumbest question ever, but when was the last time you cleaned it? The same thing was happening to me on my 650Ti until I cleaned it. Well that and sometimes my PC would shut down.

EDIT: I don't think it's throttling, the temps are really low. 

As the person above me asked, what's your PSU?

[Infernofight]

Oh yes forgot to mention that, Corsair CX600M. It doesn't happen all the time, just sometimes and with certain games. 

[Luis815]

Have you checked CPU usage and temps?