Hi, I discover this Dr. Geo Smalltalk sketch to animate is about 60% slowler on P7 compare to P3: | fig point comment x y random inArc tries| "Monte-Carlo PI approximation" fig := DrGeoCanvas new fullscreen scale: 400. fig arcCenter: 0@0 from: 1@0 to: 0@1. fig polygon: { 0@0. 0@1. 1@1. 1@0 }. comment := fig texte: '' a: 0@ -0.1. random := Random seed: Time millisecondClockValue. tries := 500. inArc := 0. [1 a: tries faire: [: try |    x := random next.    y := random next.    point := (fig point: x@y) small.    (x squared + y squared) > 1       ifTrue: [point color: Color blue ]       ifFalse: [inArc := inArc + 1 ]. comment text: 'Tries: ', try asString, ' approx: ', (inArc * 4 / try) asFloat asString. World doOneCycle. ] ] timeProfile The log are enclosed to compare. The mains differences seems to be during the world update. Years ago when porting to P3 I also see an important time performance degradation[1] and it remained unresolved. [1] http://forum.world.st/Slowness-question-tt4761717.html -- Dr. Geo http://drgeo.eu