An Examination with Valgrind exposed that the costliest functions are mutex locking/unlocking, malloc/free of charge and QImage handling. So I did some optimizations regarding QImage. In dedicate 1f976e5b5ee3cfe40921c74b97edb8d84ff39dd3 I reorganized the Smalltalk bitmap to QImage conversion which resulted in testStandardTests working time of 142 s