data when the buffer is at least 75% full or when there is no more
input to fill the buffer.
.PP
+\fIsize\fR may also be suffixed with
+.BR m ", " k ", or " b
+to indicate that it is in megabytes (2^20), kilobytes (2^10) or bytes.
+.PP
It is intended for use in situations where many small writes are
undesirable for performance reasons, e.g. tape drives.
.SH OPTIONS