Recently I’ve come into possession of my brothers pc. Before reinstalling windows I went through his pc a little bit, tried a few games on high graphics and had great performance. Now after reinstalling windows, I’m getting poor fps and stuttering. For example I tried playing Pubg and got avg 30 fps on low graphics whereas my previous pc runs 60fps low graphics. My previous pc has a gtx 760 and this one is a xfx Radeon r9 390. I’m not the best when it comes to PC knowledge but I know it should be running better than my previous pc. The performance issues are on every game including csgo and even rocket league. If anyone knows what potential issues could be, please let me know.