Question Weird OC Benchmark Result

[FranticSkunk]

Hi,

So I have an i5 8600k on a Z370-P motherboard, I have also overclocked the 8600k to 4.9GHz although what I don't understand is how my Cinebench results are less after overclocking to 5GHz than they were at stock clock at 3.6GHz, I thought that maybe it had something to do with my CPU temps although whilst running Cinebench the highest my CPU goes is 75c (167f)
I know the overclock is stable as I had ran a 7 hour 30 minutes stress test in Intel XTU,

At stock clock the score is around 2200
At my 5GHz clock the score was around 2000 - 2100

My question is why is it under preforming whilst overclocked and not overheating too badly.

PC Specs:

CPU: i5 8600k
Mobo: ASUS Prime Z370-P
Cooler: Corsair Hydro 115i
RAM: Corsair Vengeance 16GB
GPU: ASUS 1060 6GB

 

[scallumal]

Overclocking can have diminishing returns when pushed to far with not enough voltage what is your voltage at? (Undervolting)

 

[FranticSkunk]

Overclocking can have diminishing returns when pushed to far with not enough voltage what is your voltage at? (Undervolting)

I just did it with Asus' 5GHz OC Profile I'm currently at work so I'm not too sure what the voltage is on that

 

[Finstar]

Your motherboard might be power throttling. Download XTU and run a stress test to see if that's the case.

 

[FranticSkunk]

Your motherboard might be power throttling. Download XTU and run a stress test to see if that's the case.

I've already ran XTU that's what I used for the 7 hour 30 min stress test