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1 Many times faster (de)compression using multiple processors - 2012-03-07 Wed

To effectively use a system with multiple processors to do file
(de)compression you need modified software. Most tools in common
use don't have this capability - which is often a big waste
considering nearly linear speedups can be achieved in most

Switching to a parallel (de)compressor will likely supress a
few minutes (possibly hours!) of time waiting from your life.

The list below can help.

1.1 gz format is "A parallel implementation of gzip for
modern multi-processor, multi-core machines", and also a replacement
(file-compatible) for the standard gzip/gunzip tools. Use pigz
-p<threads> or pigs -p <threads> (both forms are supported).

"For gz files compression can be parallelized effectively, but
decompression can't be parallelized, at least not without specially
prepared deflate streams for that purpose. As a result, pigz uses a
single thread (the main thread) for decompression, but will create
three other threads for reading, writing, and check calculation,
which can speed up decompression under some circumstances."

Full details here:

1.2 bzip2 format

Parallel bzip2 at is a drop-in
replacement for bzip2 that is capable of using multiple threads to
perform its work. Use the -p<threads> flag for this (no space).

As a side note, xz and lzip both provide better and faster
compression than bzip2 at the cost of a greater memory usage.

Some benchmarks: (thanks,

1.3 lzma

There are multiple lzma-based
implementations & file formats. has some interesting notes about this.

1.3.1 lzip format (I am using this currently).

plzip (which can be fetched at is
a drop-in replacement for that is
capable of using multiple threads for its work. Use the -n <threads>

1.3.2 xz format

  • xz-utils
    The 5.1.1alpha (2011-04-12) version of the standard xz-utils
    ( has support for multiple threads of
    compression using the -T <threads> flag.

1.4 pcompress, a new format build from scratch for parallel compression:

1.5 .zip file format.

I am not aware of any tools capable of generating or decompressing
.zip files in parallel. If you know of any please drop me a note at
igorhvr at (supress www from the domain name in this website).

Author: Igor Hjelmstrom Vinhas Ribeiro (

Date: 2013-01-09 09:28:25 BRST

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