Is Unix stdio slow?

[Andrew Hume]

to my way of thinking the bufering problem is not solved;
the best youcan say is that we recognise several different situations
that seem to need different kind of buffering solutions.

the solution fio (fast i/o) supports best is that all I/O is buffered
and if you want unbuffered i/o, use the unbuffered routines
(say, fprint(2, instead of Fprint(2 ) which do one system call.
There is one extra hook; Ftie(ifd, ofd) has the menaing that if fio
wants to do a read() system call on ifd, it will flush any output
associated with ofd.