Is it ok if my CPU usage fluctuates when I render?


I use adobe premiere and I records with dxtory and then I change codecs my cpu uses different amounts of CPU for the render, is that normal. Here is what I mean:


I use lagarith and h.264 




This range of fluctuation is quite normal when rendering, especially when using different codecs.Don't worry about it. Even if it was going from 60%-100%, there really shouldn't be a problem. And also, different codecs stress the CPU in varying amounts.