I have a PC that has far worse specs than yours (dual core lol) and I can play and record at ~100FPS, the trick is using your integrated GPU which in your case would be Intel to do all the heavy lifting and letting your CPU cores and discrete GPU handle the game.
I only tried and used OBS and never had any issues with it, I can give you a few tips to setup yours so it has a good balance between quality and compression.
I have a PC that has far worse specs than yours (dual core lol) and I can play and record at ~100FPS, the trick is using your integrated GPU which in your case would be Intel to do all the heavy lifting and letting your CPU cores and discrete GPU handle the game.
I only tried and used OBS and never had any issues with it, I can give you a few tips to setup yours so it has a good balance between quality and compression.
i could have fix that ... but OBS will lack to record above 60FPS anyway, another solution can be limit with RTSS the Freelancer Game to 60Hz and let OBS record at those 60Hz, because if for uknown reasons game run at 100 FPS when you record at 60, probably i can see those choppy things when the encoder must create "ghost frames" along the recording, always try a multiplier or something, because below it, maybe isn't a good idea (and i have tried, i can notice a 60FPS video seeing those "ghost frames" at certain point ...
Other alternative i do is make Freelancer run on Nvidia GPU, and let the Intel iGPU to push the processing with OBS, after all the data must "pass" in such graphic (Thanks optimus xD) and i get same performance, but if you only record i will insist, use the DVR by itself, or maybe should tweak better the OBS ... i could help you with that ...