I took a dev image, and run them in two ways: the normal and headless. For each I did a: "Smalltalk garbageCollect. SpaceTally new printSpaceAnalysis" Normal one: Class code space # instances inst space percent Bitmap 3753 133 11099904 37.4 ByteString 2515 85110 6106378 20.6 CompiledMethod 19130 59452 3703463 12.5 Array 2176 77579 2561928 8.6 ...... Headless: Class code space # instances inst space percent ByteString 2515 85110 6106378 24.7 Bitmap 3753 126 6049208 24.5 CompiledMethod 19130 59452 3703463 15.0 Array 2176 77577 2561844 10.4 ...... So....even in headless mode, I have 133 instances of Bitmap, representing 24.5% of the memory.... Ok, 24.5 is better than 37.5, but I don't understand why Bitmap instances are created. Why they are needed ? is there a way to garbageCollect them? thanks Mariano