In the last episode (Jan 03), Rick Moore said:
> From: Tonu Samuel <tonu@stripped>
> > Do you have IDE or SCSI hd-s? There are many tricks what can be
> > done with IDE. I do not know much about SCSI and FreeBSD. Under
>
> IDE, but thinking of switching to SCSI. I've seen threads on this
> mail list discussing hdparm under Linux. Unfortunately, it doesn't
> seem to exist on FreeBSD or I don't know the equivalent... Perhaps
> some FreeBSD guru can enlighten me...
>
> > > - Interrupt activity is very high. About 60% of CPU activity is
> > > handling interrupt requests. Almost all the interrupts are for
> > > disk activity.
> >
> > At least on IDE this means that processor can't do anything until
> > you issue -u1 with hdparm.
>
> Ouch. Hope it isn't that way on FreeBSD.
It is; the default for the wd driver is "play it safe", which means PIO
mode. What you probably want to do is rebuild your kernel after adding
a "flags 0xa0ffa0ff" keyword to both of your IDE controllers in the
config file. That will enable 32-bit I/O, DMA, and multi-block I/O for
both master and slave. "man wd" for more info.
FreeBSD 4.0 has a completely rewritten IDE/ATA driver that can ask the
drive what capabilities it has, and enables the above options if the
drive says okay.
--
Dan Nelson
dnelson@stripped
