BumpMapping shows off the power of per pixel operations and how beneficial the addition of per pixel work is when it was added to Flash 8 with the graphics libraries and filters.
BumpMapping is great for simulating 3d depth in textures and can only be used minimally right now in flash due to the per pixel nature of the operation. It seems more work in this area is maxing out at 256×256 textures/maps.
For a quick benchmark you can see that ByteArray’s AS2 BumpMap sample is much much slower than the AS3 version. Its a small glimpse into the optimizations and reasons for graphics that AS3 is simply the best choice now. UnitZero’s BumpMap for AS2 is much faster but the comparison of ByteArray’s experiment is a better comparison since its using the same algorithm ported to AS3.