[Gdal-dev] DTED Performance on Windows

[Jason Beverage]

Hi Martin,

The performance is basically the same for all the DTED 2 files that I've
tried.  If I convert the file to a geotiff using gdal_translate it only
takes about 2 seconds to load the file.

Thanks,

Jason


-----Original Message-----
From: Chapman, Martin [mailto:MChapman at sanz.com]
Sent: Tue 3/6/2007 5:21 PM
To: Frank Warmerdam; Jason Beverage
Cc: gdal-dev at lists.maptools.org
Subject: RE: [Gdal-dev] DTED Performance on Windows
 
Jason,

If you can send me the dted or tell me which one it is (I have the NGA
DTED Library) I will test it on windows for you and let you know How
fast I can load it for a comparison.

Martin Chapman
SANZ Inc.
Software Developer
http://www.earthwhere.com
W - 303.495.6326
C  - 303.898.0397

-----Original Message-----
From: gdal-dev-bounces at lists.maptools.org
[mailto:gdal-dev-bounces at lists.maptools.org] On Behalf Of Frank
Warmerdam
Sent: Tuesday, March 06, 2007 9:48 AM
To: Jason Beverage
Cc: gdal-dev at lists.maptools.org
Subject: Re: [Gdal-dev] DTED Performance on Windows

Jason Beverage wrote:
> Hi all,
> 
> I'm having some issues with the DTED driver, especially on Windows.
I'm
> attempting to read an entire DTED 2 into memory using a single
RasterIO
> call, and I found that performance is horrible.  I read in a mailing
> list post that setting the cache size to be about 30 MB would increase
> the speed, and it does, but performance is still pretty bad on
Windows.
> 
> I ran a simple test loading the DTED with a single RasterIO call on my
> 3.0 Gz P4 windows machine and it takes about 2 minutes to load the
file
> with a cache size of 30 MB.  On my 1.2 gz Mac Mini G4, it only takes
> about 6 seconds to load the file with a 30 mb cache.
> 
> Does anyone have any suggestions on how to speed up performance on
> Windows or have a more efficient way to load up DTED data? 

Jason,

If you can file a bug report on this, I'll have Mateusz look into what
is
happening.   Other than cache thrashing, I can't think of any reason
this
should be noticably slower on windows than anywhere else.

Best regards,
-- 
---------------------------------------+--------------------------------
------
I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo,
http://osgeo.org

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