Question / Help Trying to record gameplay but major FPS drops in video

[Squiddit]

I have a pretty good computer. When playing Minecraft (the only game I have at the moment; I'm planning on getting more games soon), I get 100-400 FPS while recording (sometimes peaking at 700 when I'm not recording). However, the video output is horribly laggy with about 5-20 FPS, making the video almost unwatchable. It especially lags when I'm looking around quickly. I've included a link to video where you can see my good FPS count in game, but terrible, laggy video output.
Oh, and the video's kinda pixelated if you're watching in fullscreen. Help with that is appreciated too.

PC specs (if they help):
Processor: Intel(R) Core(TM) i5-4690 CPU @ 3.50GHz
Video card: NVIDIA GeForce GTX 750
8 GB of RAM

Video of the lag in action (In-Game FPS shown in the top left): https://youtu.be/4dxjQrSzDqo
Log file: https://gist.github.com/anonymous/eb8857b6cfdf714f146bf901344db7b3

I've tried to include enough information as possible, but if there's anything else you need to know, just let me know and I'll provide it (given it doesn't violate my privacy). Thanks in advance if anyone's willing to help.

 

[BK-Morpheus]

Limit your ingame FPS to something useful like the Refreshrate of your monitor (60Hz or maybe even 144Hz Monitor?).
Otherwise your CPU or GPU will be under 100% stress even without capturing.
You can do so by using Vsync or FPS limit ingame (if Minecraft offers those options) or with MSI Afterburner.
You could also try to enable the limit capture framerate option in your game capture source.