I'm running an i5 processor, and when the video was playing my cores jumped from the 5-10% range (background stuff I've got running) to the 25-40% range. Inter

I'm running an i5 processor, and when the video was playing my cores jumped from the 5-10% range (background stuff I've got running) to the 25-40% range. Interestingly, just switching from the demo tab to this HN tab (FF 21 on Ubuntu) drops the cores to the 10% range. They jump again when I switch back.