That's some big content!
I think the CPU usage will depend on several factors: the type of content in the clips, number of vectors or pixel, bitmap caching, Flash Player version installed on user's machine, Flash Player version you're exporting to (and AS version), etc.
One thing you can do, if you're actively scaling the content, is to set the Stage quality (AS2, AS3) to 'low' while scaling, and then restore it after you're done. This is a guaranteed CPU saver, because it reducing the amount that the FP has to render while you're scaling.
Yes, it is for video wall. And it may more than 5000 px.
But I don't really scale it in the flash file and i didn't handle anything about the scaling. It scale when doing full size of the screen. So if my content is 1000px and put it to 5000 px resolution. It will scale to 5 times more in the flash player.
So is it any different if i make the same content on 2000px stage and 1000px stage? The stage for me is just a reference size for the flash player. And the flash player will handle content depend on how many pixel show on the screen. So if i import a 200 px bitmap and scale it 50% on 1000 px stage and import a 200 px bitmap and scale it 100% on 2000 px stage, the 1000px stage will look half size of 2000 px. But when i scale the flash player to double on 1000 px stage swf, the picture quality and anything will look the same as 2000 px stage swf.
So any different between in team of the cpu, ram or etc?