I assume you are talking about Final Fantasy 13 or one of it's sequals? Or Is it Type-0?

There are little things which can be done to settings (Particularly in Nvidia control panel) to make it more playable but your GPU isn't much better than mine and I have that trouble as well. In all these games some places will be worse than others but there is no mod(at least none here and none I know of) which will work. You could try setting the affinity for 2 cores instead of 4 as I'm told that sometimes works, and I have often found that turning off the Steam overlay sometimes helps performance. There is also the possibility your GPU is too powerful and is switching to low power mode in which case you need to switch it to high performance mode in 3D settings in NV control panel. Some people also reported that plugging in a USB controller also for some reason fixed stuttering(Something about the game checking for a controller every 1 second or so until one is plugged in). These are sugestions based on FF13 by the way. They may or may not work on the others.

Quite some info, hope one of them works.
As for NV control: first thing i do is enable things like Adaptive power -> Optimal performance.

I may be quite good with computers, seeing how i also studied in that subject, but a controller of sorts is new to me :D always happy to learn. I will plugin one in a few and let you know... It may be the case, seeing as how indeed it stutters every second or so, as if something is interrupting.

OMG! Thank you!!!
I just plugged in an old logitech controller that looks like a Playstation controller and the stuttering is over!

If you were a cute blonde or red i'd kiss you :D

Now i can P.I.P. (play in peace)

Lol yeah that would be awkward as I am a cute blonde.........GUY!! HAHAHAHAHA!!! Seriously though glad I could help. Credit for this fix goes to a Level 0 Steam member called Player1 though.