Movies - DivX

Compression Rate

In this test of DivX video files, we can see just how hard it is to compress media files that are already compressed.

The best compressor of this fileset was WinRK again. It managed to takes the top place by compressing the fileset to just over 185MB. Although a space saving of 14.6MB doesn't seem much, it's pretty astounding performance when it comes to such compressed files. Even the closest contender, WinAce could only reduce the size of the archive by about 12MB.

7-Zip, Squeeze and SBC Archiver did reasonably well, achieving compression rates in excess of 5%. The other data compressors, however, showed only mediocre performance and reduced the fileset size by about 4%. Still, that was much better than ARJ32 and StuffIt. Both compressors actually created archives that were bigger than the original fileset.

Compression Speed

The speed leader was StuffIt. It only took 4.6 seconds to crunch through 200MB of DivX files. But that's because it only packed the files together with no compression whatsoever. ARJ32 did the same thing, but it was a little slower at just over 6 seconds.

The fastest compressors that actually did any real compression work were gzip, WinZip and WinRAR. They all compressed the fileset in about 13 seconds, giving them a compredssion speed of about 15MB/s. The other compressors were much slower, with WinRK and WinAce particularly slow. Both took over 3 minutes to complete the test.

Compression Efficiency

The compression efficiency rating is a simple way to evaluate the efficiency of each data compressor. This way, we can see which compressor can save the most space in the least time.

Please note that a higher efficiency rating does not mean the compressor is better. It just means the compressor has a better compression-to-speed ratio. A more efficient compressor is, of course, always more desirable than a less efficient one.

The most efficient data compressors when it comes to DivX video clips were the trio of WinRAR, gzip and WinZip. Their moderately fast compression speed, coupled with their moderately good compression rate allowed them to outperform the other compressors in efficiency. They were over 3.7x more efficient than the next most efficient compressor, bzip2.

The most inefficient compressors were, naturally, ARJ32 and StuffIt. Both did not bother compress the fileset at all, so their tremendous compression speeds meant nothing at all.