Is there some problem with my i5-4690k when turbo boost enabled ?

[vikbot]

4690k can reach upto 3.9 Ghz when turbo boost is enabled but CPU-Z and Windows 8.1 task manager is showing 3.7 Ghz as max speed of my CPU under 100% load... I have played with it's clock speed by using Intel Extreme Tuning Utility. Since then I suspecting clock speed has ran into problem. However I have restored default values from "Profiles" but still it can't reach 3.9 Ghz. BTW, my CPU cooler is Cooler Master 212x with extra fan for exhaust.

And I'm using Gigabyte GA-Z97M-D3H motherboard

Attaching some screen shots of CPU-Z

 

[das_stig]

Boosting is dependent on the thermal headroom left from the cpu's heatsink ability to cool.

 

[vikbot]

Boosting is dependent on the thermal headroom left from the cpu's heatsink ability to cool.

I'm using Cooler Master 212x with extra fan for exhaust.

 

[rgd1101]

http://www.cpu-world.com/CPUs/Core_i5/Intel-Core%20i5-4690K.html
It 3.9 only if only 1 cores is active. if it on 100% load. it will be less. 3.7 is right

 

[vikbot]

http://www.cpu-world.com/CPUs/Core_i5/Intel-Core%20i5-4690K.html
It 3.9 only if only 1 cores is active. if it on 100% load. it will be less. 3.7 is right

Thank you very much bro You just kicked @ss of my fear !