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 depth info here:
Example Command Line
Here is an example command line for AxBuild.exe that might match the command line you need in your particular environment. The line is artificially wrapped here for better display.
axbuild.exe xppcompileall /s=01 /altbin=”C:\Program Files (x86)\Microsoft Dynamics AX\60\Client\Bin” /log:”C:\Temp”
NOTE: Make sure in AX Server Config, “Enable the hot-swapping of assemblies for each development session.” should be turned off, otherwise, axbuild command will not run