LilyPond Contributor's Guide: 4.5.2 Saving time with the -j option

### 4.5.2 Saving time with the ‘`-j`’ option

If your system has multiple CPUs, you can speed up compilation by adding ‘`-jX`’ to the `make` command, where ‘`X`’ is one more than the number of cores you have. For example, a typical Core2Duo machine would use:

>     make -j3

If you get errors using the ‘`-j`’ option, and ‘`make`’ succeeds without it, try lowering the `X` value.

Because multiple jobs run in parallel when ‘`-j`’ is used, it can be difficult to determine the source of an error when one occurs. In that case, running ‘`make`’ without the ‘`-j`’ is advised.

#### LilyPond — Contributor’s Guide