Date: Tue, 16 Aug 94 15:15:28 -0400
From: dj AT ctron DOT com (DJ Delorie)
To: babcock AT cfa DOT harvard DOT edu
Cc: olly AT mantis DOT co DOT uk, djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: Speed tuning programs

> If you are doing a lot of I/O, it might help to use setbuf() or setvbuf() to
> enlarge the buffers.  I've seen this make a dramatic improvement for programs
> which do little more than copy a file.  Of course, this suggestion applies to
> both the BCC and the djgpp versions.

The default buffer is 4K, which is the size of the transfer buffer.
If you increase the buffer size, it will be broken into 4K chunks to
fit in the transfer buffer, so there's no gain there.