[Strat79]

Grab ThrottleStop, check the box that says "More Data" at the bottom and see if your multiplier or VID changes while under load. It is 20x more accurate at reading those things at a very high rate. Not saying CPU-Z isn't accurate, but it updates is very large intervals to ensure easier validations. It uses an average of the last second or 3 to get the readings, ThrottleStop updates 8x second if you click on the More Data button. See if it is still doing it with that software.

Edit: Doh, just realized you are on an AMD CPU, it may not work with them. If it doesn't, use RealTemp, as it updates speeds/temps, etc pretty fast too.