An Examination with Valgrind revealed that the costliest features are mutex locking/unlocking, malloc/free and QImage handling. So I did some optimizations regarding QImage. In commit 1f976e5b5ee3cfe40921c74b97edb8d84ff39dd3 I reorganized the Smalltalk bitmap to QImage conversion which resulted in testStandardTests functioning time of 142 seconds f