Path: utzoo!attcan!uunet!lll-winken!xanth!mcnc!thorin!clocs!davis
From: davis@clocs.cs.unc.edu (Mark Davis)
Newsgroups: comp.sys.ibm.pc
Subject: Re: scsi rll trade off questions?
Summary: Different BIOS Versions?
Keywords: scsi rll hard disk compatability BIOS
Message-ID: <8753@thorin.cs.unc.edu>
Date: 9 Jul 89 13:35:51 GMT
References: <14978@ut-emx.UUCP> <3299@copper.MDP.TEK.COM> <5532@tekgvs.LABS.TEK.COM>
Sender: news@thorin.cs.unc.edu
Reply-To: davis@clocs.cs.unc.edu (Mark Davis)
Organization: University Of North Carolina, Chapel Hill
Lines: 35

In article <5532@tekgvs.LABS.TEK.COM> keithe@tekgvs.LABS.TEK.COM (Keith Ericson) writes:
>In an earlier article byronl@copper.MDP.TEK.COM (Byron Lunz) writes:
>>In article <14978@ut-emx.UUCP> allred@ut-emx.UUCP (Kevin L. Allred) writes:
>>>...Segate has recently started marketing a
>>>low cost SCSI addaptor (ST01 and ST02) suitable for use with its
>>>ST296N 80MB hard disk.  This combination reportedly offeres about 750
>>>KB/sec transfer rate, which is comparable to the 1:1 interleve RLL
>>>transfer rate, and it is more cost effective.  Apparently the SCSI
>>
>>I received my new Gateway 2000 386/20 a few days ago.  ...
>> ... transfer rates of 440-460KB/sec!
>>
>
>Connecting the Seagate ST-02 to this same drive in an Intel 301 I got
>something around 460-480 Kbytes/sec transfer rate.
>

For some of the ST01/ST02 advertisements I have seen, the vendor tells
you to specify XT or AT.  Are there two versions of ROM BIOS on the
ST01?  The one confirmed >800 KB/sec transfer rate was with a ST01M
which has a third party BIOS.

I suggest that the poor observed tranfer rates come from the ST01 BIOS
using DMA to transfer the data.  This is a win on an XT, but looses
big time on an AT where program transfer is much faster.

One does get suspicious though, when the believable transfer rate data
is so hard to come by.

Those of you with ST01's at 400 KB/sec -- What kind of BIOS do you
have?  Have you called Seagate?  (I am not too surprised at a system
vendor just offering to replace it, but Seagate has some bucks
invested in making it work fast.)

Thanks - Mark (davis@cs.unc.edu or uunet!mcnc!davis)