Choice of fastest ColorModel?

Question

I read in several articles that it is a good idea to use the ColorModel of the screen for back buffers. Nevertheless drawing images on screen created by the following code:
BufferedImage i = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration().createCompatibleImage(WIDTH, HEIGHT, java.awt.Transparency.OPAQUE)or (which should be the same):
BufferedImage i = MyComponent.createImage(WIDTH, HEIGHT);is slower than this version:
BufferedImage i = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_3BYTE_BGR);I only tested this with Windows. Is it true that certain ColorModels are faster for certain platforms? Is it generally a good idea to use a screen compatible ColorModel, because it should perform acceptable on all platforms? Or should I ignore the wonderful platform independency of Java and use different code for different platforms?
Has anybody an idea?

Answer 1

We've done a lot of testing with this. It seems that by and large you are best off with TYPE_INT_ARGB. The 3BYTE_BGR that you use might be similar, as it is still one byte per component.
Other types, at least in our testing, cause massive memory hits and CPU consuption when they are drawn to the screen. This is caused by a conversion of the source to one of the above types.
We tested on WinXP, Linux, and Solaris. The latter two were with both local and remote displays.
Additionally, BufferedImages get cached on hardware accelerated platforms. It has been a while since I looked at the code, but I seem to remember it either uses or behaves like a VolatileImage when drawn several times w/out modification.