PC running below benchmarks - any help?

GPU - GTX 970 CPU - i5 - 4460 HDD 1TB, 7200RPM Ram 8GB, 800Mhz

Title says it all really, my PC is running below the benchmarks and I am wondering if any of my parts are bottlenecking it. I find that every game runs around 10 fps below benchmarks. Even lowering setting doesn't increase the fps by that much, In GTA 5 i experience almost no performance difference from low to high.