Frame drops and irregular GPU usage after CPU upgrade

[Breslauer]

Hi all!
I recently upgraded my CPU from Phenom II 955 (3,8 GHz OC) to FX-8350 (4,0 GHz stock) and I'm experiencing frame drops in my games that wern't there before.

My specs are:
MOBO: Asus M5A97 R2.0
GPU: Sapphire Nitro R9 380 4GB
RAM: 8 GB DDR3
PSU: Tagan SuperRock 600 W
CPU cooling: Noctua NH-U12S

1. Firstly I thought about PSU beeing not sufficient, but both CPUs have exactly same TDP of 125 W
2. Secondly temperatures of CPU are fine, around 52-55 C. The GPU temps are somewhat odd - rising even though load is not increasing? IDK
3. CPU is fine - I ran Prime95 for almost an hour, all cores functional on 100% load, no errors.
4. CPU load in Battlefield 4 gameplay never reached 100%. Cool'n'quiet disabled
5. GPU-Z shows ups and downs in GPU load. This doesn't make sense, since it wasn't the issue before the upgrade - constant 100% through Battlefield 4 gamelplay. GPUz log below (You can see the GPU load drop)

What am I missing? I kindly ask for help, I'm puzzled

 

[DonkeyOatie]

And the CPU shows no signs of slowing?

 

[Breslauer]

And the CPU shows no signs of slowing?

CPU seems to be under 38-40% load at all times

 

[DonkeyOatie]

I was more interested in it's speed to see if there is any sign of throttling. It should not because you have an excellent motherboard, but I'm checking boxes off one at a time

 

[Breslauer]

I was more interested in it's speed to see if there is any sign of throttling. It should not because you have an excellent motherboard, but I'm checking boxes off one at a time

Yep, speed is on as it should be

 

[Breslauer]

The problem was, rather unexpectedly, related just to Battlefield 4, .cfg file with FPS limit line in particular. After removing the file from the BF4 folder GPU performace is back to normal (constant 100% load).
I guess this is an issue developers or AMD should adress in any upcoming patch ?
Thank You Tom's Hardware for support, case closed