I have always known flash video will spin the fans up on my macbook pro. Then Adobe said HD flash video will only use 10% of your CPU on the new Flash 10.0, great I thought. But the fans still spin up during most flash video. I look at the process monitor and there it is Safari (or chrome) flash process 95%. However, that is a 95% share of the CPU being used, not the total CPU. So looking at the bottom of the screen it says 90% idle. So HD (and SD) flash video is running using 10% CPU (or less) and yet the macbook pro still spins its fans up high. Why do the fans need to spin up for only 10% CPU use?