8600K clock speeds fluctiating wildly

[Kezmodo]

Realised I had my Windows power settings on MAX PERFORMANCE so I set it back to "Balanced" and now my CPU is doing some weird things.

When Idle, the CPU clock speed is going wild, from 800MHz to 4.2GHz and everywhere inbetween, changing a couple of times per second. 

In the image, I was running a stress test in Prime95 then stopped it so you can see that the Turbo is still working as expected.

Is this normal with Coffee Lake? I've seen a few people reporting the same thing, maybe it's fine, but there don't seem to be any concrete answers explaining the erratic behavior.

I am running normal stuff in the background - Steam, Afterburner, CoreTemp, Corsair Utility Engine (this one I think may be causing some small issues as the fluctuation isn't as erratic when it's turned off).

I know I'm probably just freaking out over nothing, but any ideas?

[Ungefeiert]

What's your cooling solution?

[Kezmodo]

Just now, Ungefeiert said:

What's your cooling solution?

Hyper 212 Evo - replaced stock fan with a Noctua one.
Temperatures I'm not worried about and have never been an issue - CPU temp has never gone above 75C under load.

[.Apex.]

8 minutes ago, Kezmodo said:

Hyper 212 Evo - replaced stock fan with a Noctua one.
Temperatures I'm not worried about and have never been an issue - CPU temp has never gone above 75C under load.

is that fluctuation during a constant load? or at idle?

[Kezmodo]

11 minutes ago, syn2112 said:

is that fluctuation during a constant load? or at idle?

Just when idle - under load/in-game it stays at Turbo speed as expected. Very occasionally it will drop speed during games for a brief moment, but nothing that affects performance from what I can see.

[Constantin]

I have the same fluctuations? It's normal.

[.Apex.]

1 minute ago, Kezmodo said:

Just when idle - under load/in-game it stays at Turbo speed as expected. Very occasionally it will drop speed during games for a brief moment, but nothing that affects performance from what I can see.

then yeah that is completely normal, this is called Speed Shift, SpeedStep and C-States, and they're a power saving feature, if you set your Windows Power Plan to high performance it will lock your frequency at the highest, personally i don't like this power saving crap and i always set my PC to high performance.

 

and there's nothing wrong with keeping the frequency locked, it doesn't degrade your CPU or anything, it's only about power consumption and idk about the differences in power consumption, but it's not big enough of a difference to hurt the electricity bill that's for sure.

 

i think it's mostly intended for laptops since a few watts will affect battery life heavily.