[Gdal-dev] DTED Performance on Windows

[Collins, Benjamin]

All,

I'm not sure that this is the same issue, but I have seen some pretty
terrible performance generally on non-byte datasets loaded under
Windows with the NITF driver.  DTED 2 is such a file.  For me, the
gdaladdo command took 10x longer for an int16 NITF than for the same
GeoTIFF reduced to byte depth.

I can get exact numbers were it necessary,
--
Ben

>-----Original Message-----
>From: gdal-dev-bounces at lists.maptools.org 
>[mailto:gdal-dev-bounces at lists.maptools.org] On Behalf Of 
>Jason Beverage
>Sent: Tuesday, March 06, 2007 6:57 PM
>To: Chapman, Martin; Frank Warmerdam
>Cc: gdal-dev at lists.maptools.org
>Subject: RE: [Gdal-dev] DTED Performance on Windows
>
>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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