Subject: inb()/outb() performance issues..
To: None <port-i386@netbsd.org>
From: Peter B <pb@ludd.luth.se>
List: port-i386
Date: 05/27/2002 12:31:59
        Hi!

I have constructed a small eprom reader (will become burner today). Which 
connects to a "standard-PC" parallel connector. It consist of 4x LS161, 
1xLS244, 1xLS14 + 27C256. The way to control is by sending outb() instructions
directly to the port (in this case 0x378). It works ok.
The machine I'm testing it on is a 486DX33 with opti motherboard. Having 8 isa
slots only. And using NetBSD-1.5/i386.

The performance I get is 880 bytes/seconds (eprom_dump | dd of=/dev/null).
Using the exact same setup with FreeBSD-4.5/i386 gives with same program and
same machine 2017 bytes/seconds. 2.3x factor!

Should it be like this.. and why is this?

              /Peter