record what?
Sorry... it depends
Video resolution, frame rate, color depth, etc, then quality settings of recording
CPU/GPU available
Disk I/O to support recording
what else is going on the PC
OS and OBS settings
etc
There are those with subject matter expertise from years of working with OBS, that can pull off 1080p recording on old PCs. Others, playing modern games (which are already computationally intensive) can bring an expensive workstation to its knees trying to add real-time video encoding on top of existing workloads.
OBS is a powerful, flexible, video compositing tool (ie bring together various sources).
For simple recording of a screen or App window, there are far simpler free tools (including built into Windows) than OBS. I love OBS, but for me it is the right tool for the job. in your case??? not sure
