Application switching will make the CPU usage fluctuate, yes. In full-screen mode the graphics driver will try and hog all the CPU time it can get its hands on, which explains the 99% CPU time. In windowed mode it will try and be nicer to other applications.
I wrote this - http://blitzbasic.com/Community/posts.php?topic=43396 - a while back to see where my CPU usage was going. It doesn't measure total CPU usage, but it can tell you how much time each part of your program is taking and identify any bottlenecks. I don't know if that helps at all.
I wrote this - http://blitzbasic.com/Community/posts.php?topic=43396 - a while back to see where my CPU usage was going. It doesn't measure total CPU usage, but it can tell you how much time each part of your program is taking and identify any bottlenecks. I don't know if that helps at all.