Compress data, gain performance

Posted Feb 2, 2007 16:43 UTC (Fri) by daney (guest, #24551)
In reply to: Compress data, gain performance by walles
Parent article: Embedded Linux: Using Compressed File Systems

Like many things, the benefits of compression depend on the specific hardware in question.

* Slow CPU + very fast disk -> Compression might not be useful.

* Fast CPU + very slow disk -> Compression may be useful.

You really should test it on your specific configuration.

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Compress data, gain performance

Posted Feb 5, 2007 14:30 UTC (Mon) by dvdeug (subscriber, #10998) [Link] (1 responses)

But where's the line? Ignoring the outliers, I strongly suspect that the 97% of users running fairly close to off-the-shelf Intel/AMD boxes all fall into the same category, and I suspect that those running on other fairly modern off-the-shelf hardware also fall in the same boat. There's thousands of issues where it's possible that the choice may not be optimal for odd hardware, but it's far easier and more efficient to pick a standard choice than have every user check their system.

Compress data, gain performance

Posted Feb 9, 2007 11:54 UTC (Fri) by robbe (guest, #16131) [Link]

Remember that this article talks about "Embedded Linux", so your CPU is
typically puny in comparison with the CPUs you seem to think of.
Furthermore, the "disk" is often flash memory: slower than DRAM, but much
faster than a harddisk.

Benchmark results for various compressed vs. standard filesystems on a
laptop (i.e. slow mass media, fast CPU) was linked to in the article:
http://tree.celinuxforum.org/CelfPubWiki/SquashFsComparisons

My guess is that the dividing line lies between desktop/laptop and
embedded machines.

I suspect what is holding back compression as a standard fs feature in
desktop/laptop systems is the complexity of fragmentation-avoidance in
the write-often case, and that the really big data (images, films, music)
is often compressed anyway (and by means better than general purpose
algorithms can offer).