Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!bpa!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.arch
Subject: Re: Slow SCSI
Message-ID: <8696@cbmvax.UUCP>
Date: 23 Nov 89 05:35:35 GMT
References: <15249@haddock.ima.isc.com>
Organization: Commodore Technology, West Chester, PA
Lines: 24

in article <15249@haddock.ima.isc.com>, news@haddock.ima.isc.com (overhead) says:
> Keywords: Peripheral Controllers, Gather, Scatter, I/O Architecture

> On the other hand, I've seen SCSI systems perform at similar speeds
> as ESDI systems with similar bus, CPU, and OS at the high end
> (386's).  We were getting 300 Kb/sec transfers (similar to a VAX
> 780 with RA 81's running 4.3 BSD).

Not surprising, considering it's not at all unreasonable for the SCSI
device to actually have an EDSI hard disk talking to the other end
of it's SCSI controller.  The Real Nice Thing about a high level
protocol like SCSI, vs. something low level like EDSI, is that you
can take advantage of advances in drive technology without throwing
out your controller.  With our system and the latest Wren VI drives
we're getting better than a megabyte/sec, at the filesystem level.
This is still with asynchronous SCSI.  Last year the record was more
like 900 Kb/sec.  

> Stephen.

-- 
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
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                    Too much of everything is just enough