So I was shocked by Microsoft`s claim about the battery life of my SP4. How could they claim that watching a movie could last 9 hours on one charge? When I left my SP4 idle I got around 4 to 5 hours max.
Then I ran some test. When I played an unencoded video, my batter life lasted much longer. What the heck!? So as far as I can tell, when idle (not running anything including my anti-virus program) it had a low CPU usage of 2 to 3 percent. However, the CPU speed stayed around 1 GHz. When I ran a video, the CPU usage went up to 4 to 5 percent but the CPU speed went down to .5 GHz. Overall, running the video actually used less battery power. BTW, encoded videos use much higher CPU speeds and usage.
So I guess what I want to know is how do I lower my processor speed when idle. I tried lowering my min CPU speeds setting when unplugged, but it doesn`t force a lower CPU speed unless I change my max.
Can you confirm if the same is true with your SP4? And if possible, give me some ideas to lower the CPU speed when idle.