Here the idea, which came to Chris, put a delay into #finalizationProcess loop: finalizationProcess [true] whileTrue: [ WeakFinalizationList initTestPair. FinalizationSemaphore wait. FinalizationLock critical: [ WeakFinalizationList checkTestPair. FinalizationDependents do: [:weakDependent | weakDependent ifNotNil: [weakDependent finalizeValues]]] ifError: [:msg :rcvr | rcvr error: msg]. 5 seconds asDelay wait. ]. And here a simple benchmark, which triggers GC often: [ Array new: 100 ] bench without delay: '2,450,000 per second.' '2,490,000 per second.' '2,490,000 per second.' '2,480,000 per second.' '2,530,000 per second.' with delay: '2,670,000 per second.' '2,680,000 per second.' '2,690,000 per second.' '2,730,000 per second.' roughly about ~8% faster :) But now lets put something big into weak array: | dict b | dict := WeakKeyDictionary new addAll: (( 1 to: 1000 ) collect: [:i | i->i] ); yourself. WeakArray addWeakDependent: dict. b := [ Array new: 100 ] bench. WeakArray removeWeakDependent: dict. b without delay: '1,840,000 per second.' '2,060,000 per second.' '2,130,000 per second.' with delay: '3,030,000 per second.' '2,880,000 per second.' '2,890,000 per second.' Do not forget to do: WeakArray restartFinalizationProcess when you changing the #finalizationProcess method, otherwise you won't see real numbers. So, i like the idea of putting delay there. Finalization is eventual, and there is no hard guarantees that it will happen in micro-second just after some object become garbage. So, be it 5 seconds or 1000 seconds not really matters. What is matters that with delay we win much more, by avoiding wasting time in finalization process too often. -- Best regards, Igor Stasenko AKA sig.