From Forum Nokia Wiki

Would you like to speed up Symbian C++ compilation, and you have hyper-threading or dual core CPU?

You can do that by enabling parallel builds. To do that, edit the file <SDK_ROOT>\epoc32\tools\bldmake.pl. On line 1855 or thereabouts, change line:

"\t$CallMake $RealMakefile \$(CFG)\n"

to:

"\t$CallMake -j 2 $RealMakefile \$(CFG)\n"

Here "-j 2" means that .cpp files are compiled using two parallel processes.

After this change, run "bldmake bldfiles". This change should also affect Carbide.c++ v1.2 builds.

This can yield about 10% improvement on hyper-threading processor (measured on project with many modules and about 600 .cpp files). Speed up on dual core machine was 13%. When using -j 4 on dual core machine the speedup was 20%.

Problems

Q: I get error message about missing .rsg file (no rule to make <project>.rsg, needed by <project>_reg.rsc)?

A: Currently not sure why this is caused. One possible solution is to delete <project>.rsc from SDK. Actually, this is most likely not directly related to parallel compilation.