yes, snipergod is right, that means the cpu is most likely the bottleneck in your system. While playing cpu-dependent games the only ways to improve performance is overclocking or upgrading the cpu entirely.
Without knowing what game(s), what setting and resolution they are running at and the systems specs all we can do is guess. I suggest your provide more info if you want a more certain answer.
He's also Swedish, not sure if still in Sweden or just from there. Zorken, this is your FOURTH thread about changing your CPU/CPU being slow. The answer is you have the 6100, which while a good CPU for most games, it's going to have issues with some of them. You've talked about upgrading to the 6600K or 7600K, either of which is a good idea. As mentioned in your other threads, 6600K will drop in, the 7600K will work but you'll need to make sure you are on an upgraded bios before using that CPU. STOP making more threads about the same issue. The answer won't change just because you made a new thread.