Hello loopy2mn,
Thank you for getting back to us.
i make it record 4k or 360x480 it has the exact same stuttering,
1. Please go to "NVIDIA Control Panel -> Manage 3D settings -> Add 'Bandicam' -> and select "Prefer maximum performance" at the Power management mode.
2. It might be an SLI bug. Do you have the stuttering issue when you have turned off the SLI or used one graphics card?
3. If you're using Nvidia graphics driver ver. 378.49, it might be the cause of the problem.
Please uninstall it and install the latest version from
http://www.geforce.com/drivers.
4. Also please uninstall Bandicam and install the latest version and try recording again.
If you still have the problem, please let us know your format settings.
Thank you.