I have recently installed an xfx RX 580 gts black edition. its clocked at 1405mhz, and i has 8 gigs of ram at 8000 mhz. My heaven benchmark on ultra, stays at 45 fps, and stuters. Gta5 on default settings with directx 11.5 is staying at 30fps 45 on some portions of the benchmark. I am not sure why this card is performing so poorly. here are all of my specs
CPU: AMD fx 6300
RAM: Gskill ripjaws 16gb ddr3 1633mhz
Motherboard: MSI 970 gaming
PSU: Corsair 650 Watt
Videocard: xfx RX 580 gts black edition Model: RX-580P8DBDR
Please help I'd appreciate it.