Problem with i5 6600k overclock

[Janis Bergis]

Hello.
I have a problem with overclocking my 6600k.
So i have set multiplier to 45 and it runs on 4.5Ghz and my vcore on 1.35V but when i start to stress test it my voltage sometimes drops to 1.296V and frequency to 3,8Ghz.
Here is a video of my problem: https://youtu.be/SYTGhMf6MXk
What could be the cause of this?

Specs

MB: Msi z170a gaming pro
CPU: i5 6600k
Cooler: corsair H100i GTX
Psu: evga 550GS
Ram: 8gb hyperx
Gpu: Asus gtx 970

 

[Tradesman1]

The CPU and voltage will adjust as needed if it doesn't need to run 4.5 to do what it's doing it will drop, perfectly normal

 

[amtseung]

Disable EIST (Intel SpeedStep) if you want less fluctuating core clocks and don't care about the power savings. You're essentially hitting the "power target" of speedstep and it's throttling itself to meet its target. I'd also check to make sure your Cstates are set correctly.

Otherwise, your CPU is behaving pretty normally.