An Evaluation with Valgrind disclosed that the most expensive functions are mutex locking/unlocking, malloc/no cost and QImage managing. So I did some optimizations about QImage. In dedicate 1f976e5b5ee3cfe40921c74b97edb8d84ff39dd3 I reorganized the Smalltalk bitmap to QImage conversion which resulted in testStandardTests working time of 142 second