Currently, I am using using the open source, free compression software 7-zip on all my server to do backup from time to time. Using compression software to shrink file for backup, I don’t bother to upgrade the archival program because I don’t think the version make much different.
Indeed, I am making a big mistake : as in computing world, beside patching security notes, you should upgrade a new release ASAP. When upgrade the 8 months old 7-zip to the latest 4.42, the backup file archival time shorten as much as 60%. Archiving 1.7GB files inside an old P3 900Mhz just took 15minutes, as compare to 45minutes before upgrade the 7zip utility.
Oh yes, the 64bit 7-zip are insanely fast. With duo core AMD Dual core Opteron processor, compress 2500 files, total size 1.8GB under 25minutes, using the normal compression function. Impressive. 
The latest 7-zip are 4.56 beta.