I recently got an R9 380 GPU, and I play FTB Infinity evolved. So I load up the game and put the TexturePack (Sphax 128x128) and I'm getting 25 fps with drops down to 7 and I get 60 FPS in GTA V max settings. My cousins computer with a GTX660Ti handles the same TexturePack on Infinity Evolved just fine. Any help?