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Re: Performance problem
- From: Andre Bleau <bleau at igb dot umontreal dot ca>
- To: cygwin at cygwin dot com
- Date: Tue, 08 Jul 2003 16:25:32 -0400
- Subject: Re: Performance problem
If I am interpreting the output below correctly, you are developing an
OpenGL program under X11; that's the main reason it is so slow.
OpenGL under X11 renders everything in software, without any hardware
acceleration, so it's rendering is orders of magnitude slower. It is true
that Cygwin's I/O and memory management are somewhat slower than under
Linux, but that's peanuts compared to the OpenGL penalty.
If you want a fast program, you will have to use Window's native OpenGL
implementation, which renders through hardware accelerators. That's what
the OpenGL package for Cygwin provides.
Unfortunately, to use Window's native OpenGL implementation, you will have
to rewrite completely such parts of your program as window management and
Last point (before you ask): the OpenGL implementation under X11 cannot be
easily modified to use hardware acceleration, and I doubt it can be
modified at all to do so. To know why, please search the archives for this
Vladimir Baltchev <vbaltch at orthosoft dot ca> wrote:
We are about to port Unix - Irix and Linux applications to Windows using
Cygwin. However the Cygwin version is very slow compared to Linux, even I
compiled with the optimize option -O2. It is a Windows 2000, the program
is a segmentation editor using Qt, OpenGl and some image processing.
What is the reason? Is it OpenGL on cygwin, or both?
Here is the library dependency list:
André Bleau, Cygwin's OpenGL package maintainer.
email: bleau at igb dot umontreal dot ca
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