For some reasson the malloc parameter does not work for me. ArmA starts with the default Allocator even when i added "-malloc=tbbmalloc" to the Additional Parameters. It does say in the window title (arma3.exe) "-malloc=tbbmalloc" but it won't load the allocator. If i add "-malloc=tbbmalloc" in the steam launch parameters and start the game over steam it works perfectly.