ActionScript 3.0 :: Bitmap Animation Vs MovieClip Animation

After reading some articles about increasing performance, I read that if you would cache your movieclip animation to a sequence of bitmaps, that this would be much faster. So after spending lots of hours I created a bitmap animation class that converts a movieclip to a bitmapanimation.When I completed it, and did a performance test with about 40 movieclips on a stage size of (1024x900) and set the frameRate to 100 fpsIt runned on 58 frames per second. (30 mb memory) But when I tested it without converting it to bitmaps by doing it the old and simple way of adding the movieclip dynamically on the stage withalso 40 movieclips, it runned even better (61 fps). (4mb) And it did not use so much memory as the bitmap approach was doing.

Then I thought perhaps I was doing something wrong with convertinh to Bitmaps, and found on the internet also a Bitmap Animation Class, and after testing this one, I got the same result. It seems to run faster if you don't convert it to a bitmap sequence.I only have experienced negative points, like slower framerates, using more memory, and the prerendering causes a calculation performance pause when compileing. (this is even with the fix to pass the already rendered frames of the movieclip to the next bitmap animatioin class) I am now confused of what is the best way of creating better pefromance when using the same movieclip animation (like 80 times at once).