[Gdal-dev] ECW compression - Extremely slow Linux performance

[Aaron Racicot]

One quick question, are the file systems comparable (i.e. both local
disk) or could you have a network latency issue if you are processing
over a mounted file system?  Just checking the low hanging fruit before
we rip into the problem in gory detail.

A

+----------------------------------------+
| Aaron Racicot  | aaronr at ecotrust.org   |
| GIS Programmer | 503.467.0759          |
+----------------------------------------+
| e c o t r u s t                        |
| Jean Vollum Natural Capital Center     |
| 721 NW Ninth Avenue                    |
| Suite 200                              |
| Portland, OR 97209                     |
| www.ecotrust.org                       |
+----------------------------------------+


-----Original Message-----
From: gdal-dev-bounces at lists.maptools.org
[mailto:gdal-dev-bounces at lists.maptools.org] On Behalf Of Andrew
Larcombe
Sent: Friday, August 18, 2006 8:56 AM
To: gdal-dev at lists.maptools.org
Subject: [Gdal-dev] ECW compression - Extremely slow Linux performance


Hi,

I'm using gdal_translate to convert a 4000px x 4000px uncompressed 46MB 
tiff to an ECW file.

On a Windows XP laptop (Pentium M 1.6 GHz, 512MB RAM) using the latest 
fwtools download the process takes about 6 seconds.

On a RedHat Enterprise 3 powered Quad-3.8Ghz processor with 2GB ram 
using gdal-1.3.1 built from source the process takes ~120 seconds.

In each case the command used is as follows:

gdal_translate -of ECW -co "TARGET=90" OSIM_TQ3517_2004-07-07.tif
test.ecw

Does anyone have any thoughts on why their is such a considerable 
difference in speed, and what I can do to remedy the situation?

Cheers,

Andrew

-- 
Andrew Larcombe
andrew at andrewlarcombe.co.uk
_______________________________________________
Gdal-dev mailing list
Gdal-dev at lists.maptools.org
http://lists.maptools.org/mailman/listinfo/gdal-dev