Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Message-ID: <895e81b2d26ef593c0e4d0b2948940253f0b3069@Orthosoft.ca> Date: Tue, 08 Jul 2003 17:05:09 -0400 From: Vladimir Baltchev MIME-Version: 1.0 To: cygwin AT cygwin DOT com Subject: Re: Performance problem Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit The combination OpenGL X11 works fine on Unix. We are trying to use cygwin to port our applications on Windows. The cygwin's OpenGL gives us the dependency on the X11 cygwin simulation on Windows which is slow, I gess... ----------------- 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 user interface. 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 list. Vladimir Baltchev wrote: Hi there, 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: segeditorMax.exe C:\cygwin\usr\X11R6\bin\libGL.dll C:\cygwin\usr\X11R6\bin\libX11.dll C:\cygwin\bin\cygwin1.dll C:\winnt\System32\KERNEL32.dll C:\winnt\System32\NTDLL.DLL C:\cygwin\usr\X11R6\bin\libXext.dll C:\cygwin\usr\X11R6\bin\libGLU.dll c:\qt-cygwin\qt-3\bin\cygqt-mt-3.dll C:\cygwin\usr\X11R6\bin\libICE.dll C:\cygwin\usr\X11R6\bin\libSM.dll C:\cygwin\usr\X11R6\bin\libXrender.dll C:\cygwin\bin\cygpng12.dll C:\cygwin\bin\cygz.dll C:\winnt\System32\ADVAPI32.DLL C:\winnt\System32\RPCRT4.DLL c:\Vlad\build\Dev\lib\libOip.dll C:\winnt\System32\GDI32.dll C:\winnt\System32\USER32.DLL André Bleau, Cygwin's OpenGL package maintainer. -- Vladimir Baltchev Senior Software Developer @ Orthosoft R&D Inc Tel (514) 861-1837 ext 230 Email: Vladimir DOT Baltchev AT orthosoft DOT ca -- Vladimir Baltchev Senior Software Developer @ Orthosoft R&D Inc Tel (514) 861-1837 ext 230 Email: Vladimir DOT Baltchev AT orthosoft DOT ca -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/