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On Sun, 2008-01-27 at 10:58 +0100, Justin wrote: |
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> Hey guys! |
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> |
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> Yesterday I found this article |
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> http://gentoo-wiki.com/HOWTO_Speed_up_decompression_with_pbzip2 and |
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> was very happy, because I'm an owner of an Q6600. |
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> |
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> So I tried to reproduce the benchmark from the wiki article but got |
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> that bad results: |
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> |
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> test # time bzip2 -d -kf linux-2.6.23.tar.bz2 |
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> |
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> real 0m11.672s |
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> user 0m11.306s |
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> sys 0m0.367s |
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> |
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> |
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> test # time pbzip2 -d -p4 -kf linux-2.6.23.tar.bz2 |
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> |
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> real 0m25.554s |
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> user 0m24.862s |
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> sys 0m0.683s |
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> |
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> So the parallel version took more than the double time! |
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> |
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> To test whether this is a problem of my Pc I tested this on an Dual |
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> Core with the same result. |
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> |
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> An test with 7z was much better: |
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> |
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> |
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> test # time 7za x -y linux-2.6.23.tar.bz2 |
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> |
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> real 0m4.642s |
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> user 0m8.379s |
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> sys 0m0.327s |
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> |
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|
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> So my questions is what did I do wrong? |
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|
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|
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Did you compress it with pbzip2 in the first place? |
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|
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Pbzip2 can only speed up decompression of files created by pbzip2, as |
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well. Read the docs, dude ... |
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|
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p7zip has got its own implementation of bzip2, which might be faster. |
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