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From: src@scuzzy.in-berlin.de (Heiko Blume)
Newsgroups: comp.periphs.scsi
Subject: Re: ST02 - doesn't work with ProDrive Quantum S80 - Why ?
Message-ID: <1991Jan29.170527.2952@scuzzy.in-berlin.de>
Date: 29 Jan 91 17:05:27 GMT
References: <1991Jan27.042046.10471@watserv1.waterloo.edu> <1991Jan28.025339.9730@cimcor.mn.org>
Organization: Contributed Software
Lines: 47

mike@cimcor.mn.org (Michael Grenier) writes:
>There is a PD UNIX driver for the board which works fine. Using the
>raw device and big blocks a friend with a 25MhZ board can transfer
>at rates around 1.2 Megabytes per second to a Wren IV using
>    dd if=/dev/rscsi0s0 of=/dev/null bs=100k count=...

>which is much faster than many get with the Adaptec 1542. 

hey, i get 1.5MB/s with the 1542 :-)
however, it's much more important how much you get through the
filesystem. try out the boonie file system benchmark and compare
it's output to this:

              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
386/33-ISC 80   243 91.8   351 28.4   396 65.6   216 97.6   742 62.6  17.3 14.4

i'd be really interested in what you achieve with the st-02.

>Remember a few points :
>    SCSI (for almost all drives) is an 8 bit protocol. So 16 bit
>   boards may not buy you that much.
>    The AT bus even in 8 bit mode is as fast as most scsi drives
>   in async mode.

you miss an important point here. first you don't use drives in
async mode ;-), second the main advantage of 16bit and adapters like the
adaptec with bus master dma shows up when you have more than one
disk on it. 

>    Cards like the Adaptec 1542 do not run in all motherboards
>    (including the one I'm typing this message in at!).

that's the fault of your motherboard.

>I'm not saying that a $25 card like the ST-01 is better than
>anything on the market and I certainly would not want to compare
>it one on one with cards like the Adaptec with is fast bus mastering.
>I'm just saying that it not as bad as many believe.

i agree that for many people it suffices. it's a matter of costs too.
-- 
      Heiko Blume <-+-> src@scuzzy.in-berlin.de <-+-> (+49 30) 691 88 93
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