When creating a disk image (.cdr or .dmg) from a physical CD or DVD on Mac (using Disk Utility > New Image) one can choose between 'CD\DVD Master‘ and 'compressed'.
Apart from the obvious fact that a compressed image will be smaller, are there other differences? Will a compressed image for example not expand to an exact copy of the CD or DVD?
Best Answer
Master is uncompressed and does not need to be expanded to be restored. A compressed image is obviously smaller, but must be uncompressed before it can be manipulated. If performance is a concern in restoring the image then use a Master. If you can live with a little longer time, but a smaller footprint, go with compressed. Both will end up with the same result.