Cinebench score inconsistent

[Spellior]

Hi all,
I'm new here and would like to ask about an issue I have with my CPU.

I have overclocked my 8700K to 4.7GHz, running totally stable. Thermals are perfectly fine (Noctua Air cooler). I have ran multiple stress tests which have passed. In my BIOS, I have maxed out the power limit settings etc.

My problem is:
Once I start my computer and run Cinebench, the score I get is about 9400. If I let my computer stay on (on idle) for a while, say 10 mins, and then re-run the test, I only get 8700 points. Why is this?
I can see that this maybe is affected by the effective core clocks, which is during the first test at 4.7GHz, and on the other test about 4.6GHz.

Is it a setting I have to adjust? Please help.

 

[EarthDog]

Run hwinfo64 while you're running the test and see if there's a throttling reason.

 

[Spellior]

I did that. I can't see any reason the CPU would throttle. Also monitored the stress test via ThrottleStop, the C0 state was like 99% when the effective clocks were not on their max rate. It should be on 100% I guess. But I don't know how to fix it.

 

[Mr.Scott]

On your Cinebench issue, CB likes a clean boot. Makes a big difference in score.
Also, make sure nothing is running in the backround.

 

[Spellior]

I don't think it is just a Cinebench issue. Same thing when I use Prime95 for instance. Right after boot, effective clocks are at 4.7GHz. I stop the stresstest and retry it about 15 mins later, and the clocks are down to 4.6GHz~. Thus,, I think this might affect the overall performance.

 

[Spellior]

I think I found the problem. To disable C STATES might have fixed it.
How much power is going to be consumed compared to if it was enabled? Just a rough estimate?

 

[Mr.Scott]

Not enough to make a difference.