Subject: Re: SCSI controller question
To: Brad Walker <>
From: Chris G. Demetriou <>
List: current-users
Date: 01/29/1997 13:18:49
> The NCR chips are the absolutely best chips for implementing SCSI.
> BUT, they are very difficult to program properly. SCRIPTS can be
> a cobra biting you on the butt at worst and a god send at best.
> With a properly written driver and SCRIPTS it's possible to attain
> 90% SCSI bus saturation.

"What Matt Jacob said, but with correct bus speed numbers."


At least compared to other SCSI engines such as the aic 7xxx family,
and the isp1020 (which include on-board microcode storage), the
lower-end 53c8xx models (which don't include script ram, or _any_
53c8xx models using a FreeBSD-derived driver (like the one in NetBSD)
because that driver doesn't support use of the script RAM) chew a
not-insignificant amount of PCI and memory bus bandwidth (lots of
script fetches).

I think the 53c8xx is a pretty good SCSI controller, but by no means
are they the best.