Am 16.02.2010 12:03, schrieb Jan de Groot:
Did some testing with openoffice-base 3.2.0-1-x86_64.tar: compression speed: gzip: 0m28.945s bzip2: 1m21.876s xz -1: 0m49.244s xz -2: 1m18.444s xz -3: 3m34.208s xz -6: 4m41.148s
decompression speed: gzip: 0m 5.772s bzip2: 0m29.433s xz -1: 0m13.983s xz -2: 0m12.949s xz -3: 0m12.706s sz -6: 0m11.462s
size: tar: 370728960 gzip: 173262975 bzip2: 165765469 xz -1: 157099460 xz -2: 150147496 xz -3: 142961984 xz -6: 129979708
For decompression, it doesn't matter so much which xz level you choose. For compression, anything beyond -2 is painfully slow. These times are measured on a Core2Duo E4500 by compressing the single tar file. Note that -6 saves a whopping 20MB over compressing with -2, but whatever we choose is always better than gzip or bzip2.
We should measure the resident memory usage during decompression because IIRC that is a problem.