Oh recording it was the easy part. I think it was only maxing out a single core in my CPU, because Xsplit (which is also pretty CPU intensive) didn't even affect the framerate at all.
Edit: I didn't actually check, so I can't say for sure, but even with it running, nothing felt throttled, so I'm pretty sure there was plenty of unused threads.
The hard part was uploading this newly created 300MB file to youtube with a 650kbps upload. It's so low that I could barely hold a connection to any of my chatting programs.