Buffered vs unbuffered IO?

Question

I learned that by default I/O in programs is buffered, i.e they are served from a temporary storage to the requesting program.I understand that buffering improves IO performance (maybe by reducing system calls). I have seen examples of disabling buffering, like `setvbuf` in C. What is the difference between the two modes and when should one be used over the other?

Answer 1

If the hardware does it's own handshaking, leave the buffering alone.

If you are writing your own protocols, you can shut the buffering off and

then you become responsible for the handshaking and flow control.