Download and install SIW the free version is enough. Then after installing and running please click on the Video heading under Hardware on the left hand side. This will tell you what graphics card you have. You have posted HD 5800 this is the series not your actual graphics card.It could be either a 5830/5850 or 5870.Are you using Windows 7 if so is it 32 or 64 BIT? What frames per second are you getting now?
OnePlus 5T review: Hands-on