CPU overclock issues

[Johny_Waker14]

I am experiencing a kinda weird issue :  After having successfully overclocked my e8600 cpu to 3.9 GHz and booted to windows I have been noticing in the taskmanager that the cpu isn't 100% utilized (max cpu usage from the system is 93 %) and clockspeed doesn't come close to 3.9 GHz but caps at 3.60 - 3.64 Ghz, even if the system is under high enough workload for the cpu to oparate at its maximum pontetial this just never happens.....

I would also like to point out here that the bios and cpu-z constantly report 3900 MHz and that I am using the "High Performance" preset under the power options menu. Also by having tried to overclock higher ex: 4.1 GHz, I noticed again that the cpu would run about 200-400 MHz lower that the overclock that I previously setted and it would not be fully utilized by the os.

 

I have already tried disabling C1E and speedstep but nothing works. 

 

 

Build : And yes I know that for modern standars this is total CRAP but it is what it is and it's mine so.....yeah

 

CPU: Core 2 Duo E8600

RAM : 7gb 667 mhz, overcloked to 800mhz

MB: Asus P5K

GPU: 710 gt

OS: Windows 10 64bit

Bootdrive: Verbatim Vi550 S3 SSD

Cooler: Arctic 11 LP

 

PS: Sorry for any bad grammar or spelling as English isn't my mother language in my country

 

[aDoomGuy]

Task manager may not give you the correct information due to overclocking. Check with one or more of the following applications.

 

HWInfo (free)

Aida 64

HWMonitor

 

But you already used CPU-z so there you go.

[Johny_Waker14]

Ok, actually I already though about this chance but what really troubles me is that the os was behaving like this even before the overclock ! (sorry i forgot to write about that in the problem description). So I am kinda convinced that I must be missing something . Or there is also the miniscule possibility that windows is just reporting wrong from the beginning (who would expect it ?)