[FWTools] gdal_* translate and memory usage Ubuntu

[Frank Warmerdam]

Shaun Kolomeitz wrote:
> Dear FWtools list,
> 
> I've setup an Ubuntu 6.10 (Edgy Eft) server on a Dual Xeon Dell (3.0Ghz)
> machine with 4GB RAM and am comparing it to my FWtools install on Dual
> Xeon (3.2Ghz) HP WindowsXP (4GB RAM).
> On Windows I am able to allocate (using -config GDAL_CACHEMAX 512) MB of
> memory for example, and it will happily use up to and sometimes over
> this amount.
> In Ubuntu however I only see the memory allocation go up to about 20 MB,
> even if I renice the process to a maximum priority. Also converting
> takes about twice the time on Ubuntu (even though the IO subsystem is
> much faster - SCSI320, than my SATA2 Windows machine). Memory speed is
> definitely faster, CPU slightly faster on my Win machine though.
> Does anyone know if there are other settings in *nix that would affect
> this, or is this running as one would expect ?
> I have some screen snaps if this would help.
> http://fwtools.maptools.org/

Shaun,

The GDAL tile caching logic will work the same on linux and windows.
However, without knowing more about the operation you are doing it is
hard to know what may be affecting performance.

I will say that what counts as "process memory" may vary substantially
between windows and linux.  For instance, on linux disk io caches
maintained by the operating system do not count against any process.
They may (I don't know) on windows.

Without knowing the format, file size and actual operation you are
doing I can't suggest much more.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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