Luckily for you, if you have any modern NVIDIA Geforce card (600 Series or Newer), there is a video encoding hardware built onto your graphics card to allow you to record with very little performance hit.
Don't know if you have an NVIDIA graphics card?
Hit ctrl+shift+escape or open up Windows Search and type "Task Manager"
Now make sure you have Geforce Experience installed. This is NVIDIA's software to handle Driver updates for your Graphics card that also comes with Shadowplay.
If you're unsure if you have installed, hit Windows Key and search for it.
If you don't have it, go ahead and install it from NVIDIA's website.
https://www.nvidia.com/en-us/geforce/ge ... xperience/
Once you have it installed, pop it up and click the little button to open up the Overlay.
Once you have it opened, go ahead and turn it on and set the duration. Notice the hotkey it shows you for saving. You can change the hotkey in settings, by default it is Alt+F10 I believe. You can hit that button at any time to save the past
You can click the cogwheel in that menu to and then "Recordings" to see where the video is saved on your computer. It is saved as MP4's, you can just go to that folder and upload to Youtube/use Windows Photos to trim the video, etc.
You can get in contact with me on Discord Miku#2402 or join our Discord for support at https://pandahut.net/discord.