[Solved] Use of multi-core for compiling on Windows for MSVC
I am wondering, if there is not a way to compile with MSVC on Windows and using multiple cores.
I had to compile Qt on Linux a couple of times lately. The use of multiple cores with "make -j<x>" came in quite handy. Today I have configured a cross-compile with "nmake -j<x>" and nmake complained. Now the compilation takes for ever while 3 of 4 cores are idle.
What am I missing?
native nmake does not support this - unfortunately.
There is a modified version, called "jom", made by our beloved Trolls. Some infos in this older blog post "Speeding up Visual C++ Qt Builds":http://labs.qt.nokia.com/2009/03/27/speeding-up-visual-c-qt-builds/ and in the gitorious repos at http://qt.gitorious.org/qt-labs/jom
Have you tried to build Qt to see how many cores are used?
Since with my system the VS2010's nmake by default is using both the cores available, so i guess you don't need anything.
Thanks for hint. I will follow up.
I am using VS2005 on Win7 (64bit). In general I can use the parallel building process with my own source.
The Qt compilation I am doing from the command prompt after using configure. There you have to start nmake and that is the point I got stuck.
Then use jom, or for VS2005 you can also add -MP to the QMAKE_CFLAGS from qmake.conf file located in mkspecs\win32-msvc2005
//i didn't try this - because i didn't use that VS and 2010 use both my cores by default
For those of you looking for the same solution.
[quote author="Volker" date="1305107505"]
There is a modified version, called "jom", made by our beloved Trolls. Some infos in this older blog post "Speeding up Visual C++ Qt Builds":http://labs.qt.nokia.com/2009/03/27/speeding-up-visual-c-qt-builds/ and in the gitorious repos at http://qt.gitorious.org/qt-labs/jom[/quote]
Go directly to the gitorious repos. The download link on the blog delivers an old exe.
Or use the "FTP site directly":ftp://ftp.qt.nokia.com/jom/
It works great !!!
A suggestion for Qt: Include it in the distribution.
I have tried both nmake (VS2010) and jom.
jom keeps the laptop doing some 100% usage almost all the time.
nmake was not able to do more than 35% at any time and was doing 20% most of the times.
i got a i7 with 8 cores, all engaged 100% and even the fan on the back of the laptop.
jom is good, .. so jom.