GTA and other games use 3D acceleration.
I'm writing about 2D acceleration problems. Read carefully!
Compare 2D GDI performance - Discrette vs Integrated.
Test #1: Discrette graphic card - Radeon R7 360. Very low performance
Test #2: Integrated CPU Intel i5-6500 - HD 530. Normal performance
Resume: ABSUR!! Integrated CPU i5-6500 HD530 has higher 2D performance than the discrette Radeon R7 360.