Hahaha XD , If you are playing gta san andread and you expect it to run at 100% , than don't worry.
This is such a low demanding game for now that your card will not run at 100%. You would have had like 1000 fps if it did. If it's not stuttering at san andreas than you are good. The power limit is changable in msi afterburner. Try to play the witcher 3. I have my own experience with rainbow six siege and I know that it doesn't run well sometimes on some rigs and it's normal. Run the heaven benchmark , play the games I mentioned as well as try it on ghost recon wildlands if you can on low settings. Try to overclock your card as well. Here is how. : https://www.youtube.com/watch?v=vUEMS-B1Siw