Subject: Re: pciide performance on alpha
To: Andreas Johansson <>
From: Manuel Bouyer <>
List: port-alpha
Date: 08/13/1999 11:14:49
On Thu, Aug 12, 1999 at 10:57:07PM +0200, Andreas Johansson wrote:
> Yep, it seems to work as good as I had hoped - I think this disk is also
> maxed out with modest cpu usage:
> ajo@ymer /home/ajo #time dd if=/dev/rwd0c of=/dev/null bs=64k count=8192
> 8192+0 records in
> 8192+0 records out
> 536870912 bytes transferred in 34 secs (15790320 bytes/sec)
> 0.033u 1.550s 0:34.44 4.5%      0+0k 0+0io 0pf+0w

Nice drive !

> > Do you have the BIOS ROM on your board ? If so try to remove it.
> > Maybe the alpha firmare tries to run it (with i386 emulation, as it is done
> > for VGA) and it gets this really wrong.
> It seems that the pci registers had been changed in software while I was
> trying to get things to work - I coldbooted the machine, and the channels
> were enabled without me having to force-enable them.

Ok, that is consistent with the infos I have - at power-on the board is

> Now only the problem with bad I/O addresses remain. This is what I get
> (and change) in my SX at boot time. I have to take back that about
> overlapping addresses, I was masking too much (different masks for
> mem/io). It seems the firmware simply thinks that IO addresses above
> 0x10000 are ok (which they probably are in the alpha), but NetBSD wraps IO
> addresses higher than 0xffff. If I don't change the IO addresses, I get a
> machine check as quick as the driver is accessing the registers.

If adresses above 0xffff are ok on the alpha (Jason, is this true ? You know
alpha hardware better than me :) then NetBSD certainly does the rigth thing
(otherwise a lot of other drivers would fail as well).
My guess is that the promise chip, which was specifically designed for
PCs, doesn't support it.

Manuel Bouyer, LIP6, Universite Paris VI.