Path: utzoo!attcan!uunet!convex!killer!mit-eddie!bloom-beacon!arktouros!dyer
From: dyer@arktouros.MIT.EDU (Steve Dyer)
Newsgroups: comp.unix.xenix
Subject: Re: Future Domain SCSI controller for AT bus
Message-ID: <7521@bloom-beacon.MIT.EDU>
Date: 18 Oct 88 02:43:44 GMT
References: <522@m3.mfci.UUCP> <1988Oct10.131128.3477@ateng.ateng.com> <7077@icdi10.uucp> <1988Oct17.113009.8481@ateng.ateng.com>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: dyer@arktouros.MIT.EDU (Steve Dyer)
Organization: MIT Project Athena, Cambridge MA 02139
Lines: 25

In article <1988Oct17.113009.8481@ateng.ateng.com> chip@ateng.ateng.com (Chip Salzenberg) writes:
>Perhaps I was mistaken about 2.3 including Adaptec support.  My info was
>second hand.

XENIX 386 2.3 has several different versions, not all of which are out yet.
There will be a version released which supports the Adaptec card for
boot and root devices.

>The slowness may be due to the [Future Domain] controller or the driver
>or both.  In truth,
>I don't care; it's just too slow.  I'm ditching Future Domain as soon as
>possible.

This is good and useful information.  It's also in direct contradiction
to Future Domain's literature, which makes the point that PIO can often
be faster than DMA on a 386AT architecture due to its ability to handle
arbitrary block transfers into virtual memory versus breaking up a
request into 4kb physical DMA transfers.  I'd be interested to know
what "too slow" is here.  How does it compare to your experience
with ST506 controllers under XENIX?

---
Steve Dyer
dyer@arktouros.MIT.EDU
dyer@spdcc.COM aka {harvard,husc6,ima,bbn,m2c,mipseast}!spdcc!dyer