If you run MS Dynamics AX 2012 R2 CU 7 kernel you can do the X++ compile a lot faster using axbuild.exe because it runs in parallel executing on the AOS instead of AX client.

You may find more in debth info here:

http://blogs.msdn.com/b/axtools/archive/2013/11/04/parallel-x-compilation-for-microsoft-dynamics-ax2012-r2-in-cumulative-update-7.aspx

http://msdn.microsoft.com/en-us/library/dn528954.aspx