Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Editing › Background Rendering of Timeline Premiere › @jk this thread will help
@jk this thread will help you understand while you are having issues
As far as watching and rendering. Computers DO NOT do multitasking bi-lateral. In other words, if using a dual core processor 1 core plays the video and 1 renders the video. Some processors are able to handle this kind of tasking, but the software itself must be written to take advantage of this feature. And herein lies a problem, just because a computer maker or software maker says it can, does not mean it will, software code is a tricky thing to write (I started writing code in 1982).
So what is happening, think of it more as switch tasking and not multitasking. So what has to happen faster then you can think, is the processor stops working on the rendering then plays a bit of the clip, back and forth, back and forth, but in nanosecond times. With that there is a problem, if your computer is using its CPU to both render and play, then the data pathway from the CPU to the memory (where your rendering and playing lays in wait) get clogged, and bam your video skips, but guess what else will skip or have a hiccup in it, yes the video you are rendering.
It is important to keep in mind makers of software and computers need to sell their goods so they will market multitasking as a viable feature even in rendering software. I do not do playback and render as the same time because of potential issues and flaws that can be made in rendering and more so if you are using a laptop. The above thread I pasted here will be of help.