How do gradients in bitmaps affect CPU?

[Ray Beez]

I'm confused by a tip in Adobe's own documentation that says:

Avoid using gradients, because they require many colors and calculations to be processed, which is more difficult for a computer processor to render.

http://help.adobe.com/en_US/Flash/10...af6-7b1ba.html

I understand how this would be true in a vector shape fill, but they aren't specifying vector. It seems to be implied they include bitmaps too, since the next couple tips are bitmap related.

If they do in fact include bitmaps in this tip, can someone explain to me how this is possibly true? In a bitmap a pixel is a pixel. I don't see how it matter that the pixels form a gradiated color or not, the software still has to read and write each pixel regardless.

[jAQUAN]

Perhaps that refers to the final draw to the screen, separate from the calculation of the pixel color. You can always build a quick benchmark that draws thousands of squares randomly with and without gradients with an FPS meter.