Hi - I don't have a need for a big image. I just discovered I have no idea how to make one larger than ~512MB, and am curious. I was running into an out of memory error and discussing it in a thread on pharo-users list (http://forum.world.st/running-out-of-memory-while-processing-a-220MB-csv-fil...). The details of that discussion aren't pertinent to this question. This script below ought to make an image that maxes out well above a GB but cannot cross 512MB without throwing an OutOfMemory error. | them | them := OrderedCollection new. [[them addLast: (ByteArray new: 16000000). Transcript cr; show: ((Smalltalk vm parameterAt: 3) / (1024*1024.0) printShowingDecimalPlaces: 1); flush] repeat] on: OutOfMemory do: [:ex| 2 to: them size by: 2 do: [:i| them at: i put: nil. Smalltalk garbageCollect]]. Transcript cr; show: ((Smalltalk vm parameterAt: 3) / (1024*1024.0) printShowingDecimalPlaces: 1); flush. them := nil. Smalltalk garbageCollect. Transcript cr; show: ((Smalltalk vm parameterAt: 3) / (1024*1024.0) printShowingDecimalPlaces: 1); flush In the transcript you will see an output of the image size as more ByteArrays are added to the OrderedCollection. On my laptop with 4GB of ram it always peaks at just over 500MB. Setting the memory from the command line (e.g. pharo-ui --memory 1000m Pharo.image) does not help. Is there a VM flag that I need to flip? Thanks Paul