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Compression times

The times measured were from user seconds when running on a 2.4 GHz celeron. This measures only the user times of the tools so the actual times would be much longer (user times don't include the system calls) but I don't really care about measuring the speed of my hard disk so its more relevant. Also do note the lack of ace results as there are no Unix ace compressors.


7z 23.2
arj 5.51
jar 6.21
lha 14.26
rar 10.81
sit 11.45
tar.bz2 7.02
tar.gz 10.37
tar.lzo 20.69
tar.Z 2.51
zip 9.36
zoo 1.28
Here 7z shows its weakness. Not only in this test but across the board it consumes around two to three times the average time. tar.lzo also uses a lot of processor time despite its poor compression score.


7z 34.9
arj 3.67
jar 5.15
lha 11.26
rar 15.38
sit 30.7
tar.bz2 19.02
tar.gz 5.43
tar.lzo 16.35
tar.Z 4.99
zip 4.53
zoo 10.35
Sit compressor seems to have a spot of trouble with these jpegs. It spends a lot of time trying to compress the not very compressible.


7z 242.13
arj 30.75
jar 22.58
lha 77.02
rar 86.28
sit 111.47
tar.bz2 76.37
tar.gz 73.04
tar.lzo 159.21
tar.Z 31.3
zip 44.73
zoo 9.43
The kernel results are pretty average but due to its large size it can be used to show how much additional time is spent on system reading/writing files etc. In this case it was around 16 seconds in all compressors. This means that trying to drop below a few seconds compression time would result in very little performance improvement. That said most compressors do take considerably longer than 10 seconds.


7z 89.43
arj 16.61
jar 19.48
lha 68.33
rar 55.54
sit 68.63
tar.bz2 53.48
tar.gz 30.38
tar.lzo 63.8
tar.Z 12.88
zip 32.92
zoo 11.31
This is the final compression time graph but you can see the graph of all tests.

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