As you know new intel CPU uses a system with two core types, big and small, to save power. The windows scheduler direct the workload to the big or small cores in a way that would be very bad for video renders:
https://www.anandtech.com/show/16959/intel-innovation-alder-lake-november-4th/3
However, this way of doing things might be a bit of a concern, or at least it is for me. The demonstration that Intel performed was where a user was exporting video content in one application, and then moved to another to do image processing. When the user moved to the image processing application, the video editing threads were moved to the E-cores, allowing the image editor to use the P-cores as needed.
Now usually when I’m dealing with video exports, it’s the video throughput that is my limiting factor. I need the video to complete, regardless of what I’m doing in the interim. By defocusing the video export window, it now moves to the slower E-cores. If I want to keep it on the P-cores in this mode, I have to keep the window in focus and not do anything else. The way that this is described also means that if you use any software that’s fronted by a GUI, but spawns a background process to do the actual work, unless the background process gets focus (which it can never do in normal operation), then it will stay on the E-cores.