What are your Bandicam video recording settings? Which codec do you use? Try "MPEG1 VBR" with Quality set to 100, audio as uncompressed / PCM. A case I personally had: Check whether your GFX card really runs as PCIe 3.0, since bandicam uses that PCIe access to capture the video the game an...

Do you have the "fps overlay" from bandicam active? Try turing it off. It can slow down in some "way above usual limits" cases, like your 300+ fps. I have the same effect when I run games at 6k, 8k or 16k.

What codec do you use? Try the "MPEG1" with a high quality setting, which uses the least CPU resources, and uncompressed audio, might work better. As for GTA-V specific: The game limits to 60 fps, no matter what the settings are, so if bandicam tries to get 60 fps and GTA tries to get 60 f...

It does limit the FPS, but only when recording. I use that method to get constant 30 fps for my Ultra HD recordings, even if the game runs at much higher fps when not recording. I recommend to turn off vsync for such a setting. If you don't record you won't have luck with bandicam, you'll have to di...

The usual problem: Game crashes. You have to "force stop" the bandicam recording, leaving defective .avi files around. The bandicam avi fixer tried, but the last few seconds (technically: the last unclosed GOP) is missing. Not good. If you use ffmpeg.exe you will get everything including t...