Results from fast will be faster to compress but will not be as small. When testing the overall performance of an algorithm, it is helpful to pick a common situation, and evaluate the time, size and relative benefits of each. Test files are the combined files from the Calgary and Canterbury corpuses. These are standard sets of test files used by compression researchers to compare algorithms to each other. These are not files that Aladdin created.
Times are in seconds, size in bytes.
Thus, using StuffIt 5.0 instead of 4.5 would save a total of 2 minutes for each download, totaling 334 hours saved for all 10,000 downloads. For users who compress to save disk space, the compression and decompression size usually are more important than compression speed, especially when backing up to a floppy disk.