[Lzip-bug] performance: gzip, lzip, xz

[John Reiser]

Hi,

I ran a comparison of gzip, lzip-1.7, and xz-4.999.9-0.1.beta.
lzip has an advantage in smaller memory size needed for decompression
(in this case 8MiB for lzip vs 64MiB for xz)
but xz is better than lzip in compression speed and compression size.
xz offers filters today; lzip may have filters in the future.
The compiled size of lzip is about half the size of xz.
lzip has a smooth cost as requested effort increases;
xz has an unusually large jump in compress time from -2 to -3 effort.
Does lzip offer other advantages?  What is the comparision
for detecting and recovering damaged files?


The input file is a initramfs for booting Fedora 12.

compress
time      size      type ("-N" compression)
------  --------  --------
        26856448 .orig

gzip-1.3.12-11
 0.851s 12170822 .gzip.2
 0.991s 12018271 .gzip.3
 1.099s 11687436 .gzip.4
 1.342s 11466564 .gzip.5
 1.885s 11370564 .gzip.6
 2.336s 11344104 .gzip.7
 3.973s 11318593 .gzip.8
 5.665s 11306990 .gzip.9

lzip-1.7
10.762s  8936001 .lzip.2
12.021s  8814468 .lzip.3
14.385s  8626471 .lzip.4
17.499s  8527765 .lzip.5
20.644s  8474297 .lzip.6
22.743s  8444650 .lzip.7
23.971s  8445876 .lzip.8
25.686s  8433049 .lzip.9

xz-4.999.9-0.1.beta
 4.149s  9441928 .xz.2
14.459s  8683376 .xz.3
15.317s  8558264 .xz.4
16.372s  8497424 .xz.5
19.180s  8417640 .xz.6
19.789s  8387736 .xz.7
20.112s  8371552 .xz.8
20.152s  8371552 .xz.9

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