Which games?
It's pretty common for games to have framerate caps, as unless you've got a good enough monitor there's not much point pushing past 60 fps as it just means the card is working harder than it has to. I for example have a monitor that doesn't even really need that high a frame-rate so I limit games where I can to 30 fps to reduce load on the system (no point running your hardware to destruction for no reason 😉)
There are also framerate syncing features these days that limit a game's frame-rate to what your monitor can handle, again to avoid wasting time on rendering frames you won't actually see, so these can limit you as well.
If you're looking to find out what the max performance of your system is then what you want to do is run benchmarking tools; many games these days have benchmarking tools or demos you can run which disable any frame rate limits so you can see what your maximum is, while leaving the limit in place for regular gameplay. The procedure for running these is often specific to each game though so you'll need to look it up.
So yeah, I doubt you have an actual bottleneck in the system, it's likely a framerate cap or sync feature that's limiting you, but these are things you usually want to keep on so your system isn't running at 100% the whole time. Have a look for a benchmark you can run and it should get you much higher and give a clearer picture of what your system can actually do when pushed 😉