Asus Notebook X550IU got fps drop and stuttering, how to solved it?

Hi guys, I just bought Asus Notebook X550IU because I saw many reviews recommended this notebook for working and gaming at the same time.

Then I installed my favorite game, Black Squad on Steam and had this fps drop and stuttering in Very Low setting 1600x900.

I recognize this problem happens when there are many texture and gun trail (from 70 fps can drop to 30 and stuttering).

But what makes this a problem because I've played on my old notebook with older GPU (2GB, 128 bit) and didn't get this problem. (70-110 fps, Very Low, 1366x768).

 

I had done many changes on my laptop such as:

- used recommended AMD software (whql-win10-64bit-radeon-software-crimson-relive-17.7.2-july27)

- changed everything to maximize performance in AMD Settings and Power Plans

- decreased maximum power state to 90% (and it has a good effect to reduce heat from CPU and stabilized GPU core)

 

I also did some test like:

- 3DMARK Fire Strike, got similar score from reviewer website on this notebook.

- GPUZ Sensors, got maximum Core Clock and Memory Clock when playing Black Squad

- Playing PUBG, got 20-30 fps in very-very low setting and got stuttering (1280x720)

 

So, my temporary conclusion is the GPU is not compatible with Black Squad

 

I hope You guys can help me to overcome this problem. Maybe there's something that i missed. It will be great if You guys can also help me to play PUBG smoothly

FN: Sorry for my bad English XDDD

 

Appendix: ASUS Notebook X550IU Spec:

- CPU: AMD Quad Core FX-9830P, up to 3.7GHz

- GPU: Primary: R7 Grapichs (1GB DDR4)

            Switchable: RX 460 M (4GB DDR5, 128 bit)

- RAM: 8GB (+ 8GB)

- HDD: 1 TB

- Display: 1920x1080, 15,6 inch