OBS core team member here, just a quick clarification on this post. OBS will not run without a supported GPU for compositing; that is always handled by the GPU running on OpenGL (for macOS and Linux, we use Direct3D on Windows). The available encoders, however, might change based on the available hardware. Hardware encoders are, generally, much faster and lower impact on system resources, but may have lower quality per bitrate as a trade-off.