Wierd Clock SPeeds!

[nunocv]

Hello, recently I installed windows 10 from scratch in a ssd, and i've noticed some wierd stuff!

 

Before when I had windows 7, my clock speeds in every game where stable at 1433mhz in my gtx 970.

Now I was playing a game (Elder Scrolls Online, and happends to WoW too), and when the game was minimized, clock speed was high, when I maximized the game, the clock speed goes too 9xx Mhz max of 1100Mhz

What in the world is this? But there was times that even minimized it didnt go to 1433Mhz... And it takes fps from the game!\

 

Btw i see the Clock Speed in Afterburner.