Hey, i'm experiencing very LOW FPS when i'm playing FPS. My average fps is 25-30.
AMD Radeon HD 5800 Series
AMD Phenom(tm) II X4 965 Processor (4 CPUs), ~3.4GHz
16 GB RAM
Windows 8.1 PRO
64-bit
If it helps. Dont know what the problem is.
On that link you´re going to see a chart, your gpu is going to be between a hd 6850 and a hd 6870, that´s in ultra settings so maybe add 10 or so fps and that´s what you´re supposed to get with your build.