> If you have lots (well, a resonable amount) of memory it's also worthwhile
> adding 'CFLAGS+=-pipe' to /etc/mk.conf. This will stop gcc from passing
> data using temporary files. It also wins since one or more of cpp/cc1/as
> can run while other(s) are blocked waiting for I/O completion.

Given large memory, it's hard to have a common solution; for kernel
compiling purpse, '-pipe' brings big win.  Given more memory and
luxurious CPU power, make '-j N' parallelism provides higher gains
because every process might be on memory in any moment.  And, kernel
make involves astonishingly large number of files to be read,
increasing BUFCACHE ratio might contribute (The last phrase should be
re-evaluated when UBC is implemented in NetBSD).  For 'data
generating, write intentive on disk' environment, above makes less
sense.

Tohru Nishimura
Nara Institute of Science and Technology