5.x SLOW - How do I speed it up?

What are all the options one needs to change before doing a 
buildworld/installworld
to make sure all the debugging features are off?


> NOTE TO PEOPLE WHO THINK THAT FreeBSD 5.x IS SLOW:
>         FreeBSD 5.x has many debugging features turned on, in
>         both the kernel and userland.  These features attempt to detect
>         incorrect use of system primitives, and encourage loud failure
>         through extra sanity checking and fail stop semantics.  They
>         also substantially impact system performance.  If you want to
>         do performance measurement, benchmarking, and optimization,
>         you'll want to turn them off.  This includes various WITNESS-
>         related kernel options, INVARIANTS, malloc debugging flags
>         in userland, and various verbose features in the kernel.  Many
>         developers choose to disable these features on build machines
>         to maximize performance.