[comp.sys.ibm.pc] scsi rll trade off questions?

allred@ut-emx.UUCP (Kevin L. Allred) (07/08/89)

I'm putting together a low end workstation for my personal use at home.
It will have a 386SX, 4MB memory and monochrome VGA graphics.
Initially I plan to just run MSDOS, but soon I would like to run UNIX.
I currently am considering hard drives in the range of 65 to 80 MB.  I
was only considering an RLL drive with 1:1 interleve controller until
I had pointed out to me that 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
addaptor works fine under DOS, but I have already had related to me
that it probably won't work with UNIX because of lack of drivers (I
heard that was a problem common to most SCSI boards even the expensive
intelligent ones like the WD7000).  Are the various UNIX vendors
developing drivers, so that I don't need to worry about this, or
should I stick with the RLL controller and disks?

-- 

	Kevin Allred
	allred@emx.cc.utexas.edu
	allred@ut-emx.UUCP

byronl@copper.MDP.TEK.COM (Byron Lunz) (07/08/89)

In article <14978@ut-emx.UUCP> allred@ut-emx.UUCP (Kevin L. Allred) writes:
>I'm putting together a low end workstation for my personal use at home.
>It will have a 386SX, 4MB memory and monochrome VGA graphics.
...
>I was only considering an RLL drive with 1:1 interleve controller until
>I had pointed out to me that 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.  It arrived with
a Seagate ST296N and SCSI controller (not sure of the model #).  Transfer
rate was one of my reasons for purchasing this system, and I was assured
prior to the purchase by the salesperson that I could expect 800KB/sec.
I was quite disappointed when both Spintest and Coretest 2.7 gave me
data transfer rates of 440-460KB/sec!  Then, just today Mark Davis
<davis@cs.unc.edu>, reported that some users are seeing transfer 
rates of 950KB/sec!  

The interesting part is that when I called Gateway, the salesman
immediately began reciting what sounded like a prepared statement to
the effect that Seagate had lied to them!  Then he quickly offered
me a ST4096/DTC controller combo as a replacement, with a transfer
rate of 550KB/sec.  It's in the mail.  If someone out there is 
actually seeing transfer rates around or over 800KB/sec, I'd sure
like to hear about it.

P.S. The drive documentation supplied with my system says the
  interleave is 1:1.  And the access time, rated at 28ms, is measured
  at 33.7ms by Coretest.
-- 
Byron Lunz
Tektronix Logic Analyzer Division
byronl@copper.MDP.TEK.COM
Beaverton, Oregon

neese@adaptex.UUCP (07/08/89)

If you choose to use the Adaptec AHA-1540 SCSI host adapter, support
for this board is already included in SCO 2.3GT and ISC 2.0.  This
adapter in combination with a Quantum Pro80 will yeild a data rate
of about 2.8MBytes/sec under DOS and is one of the fastest combinations
for Unix.


			Roy Neese
			Adaptec Central Field Applications Engineer
			UUCP @ {merch,texbell,killer}!cpe!adaptex!neese

keithe@tekgvs.LABS.TEK.COM (Keith Ericson) (07/09/89)

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.  It arrived with
>a Seagate ST296N and SCSI controller (not sure of the model #).
>Spintest and Coretest 2.7 gave me data transfer rates of 440-460KB/sec!
>
>If someone out there is 
>actually seeing transfer rates around or over 800KB/sec, I'd sure
>like to hear about it.
>
I've evaluated the Adaptec AHA-1540 SCSI controller and the Western
Digital WD7000ASC connected to a 300 Megabyte CDC Wren 4.  With both
cards I got transfer rates slightly in excess of 1 Megabyte per second
in any of our '386 machines (we have Intel 301's (16 MHZ) and step 20's
and 25's (20 and 25 MegaHertz respectively.)

Connecting the Seagate ST-02 to this same drive in an Intel 301 I got
something around 460-480 Kbytes/sec transfer rate.

A WD7000ASC connected to a 150 Megabyte version of the CDC drive in my
'286 box (8 MHZ, I think) yields 818 Kbytes/sec.

In our Step/33 we've got an Adaptec 2332 (2322?) ESDI controller
connected to a Maxtor 380 Megabyte drive (I forget the model number).
It clocks in at just under 1.4 Megabytes per second transfer rate.
(That's right: almost 1.4 megabytes per second.)  This is a 15
Megabit/sec drive/controller pair.  The same controller connected to
another drive (mfgr and model I've forgotten) which is a 10 Megabit/sec
drive yields about 700- to 800-Kbytes/sec transfer rate.

All transfer rates reported with CORE27 and running MS-DOS.

kEITHe

mike@cimcor.mn.org (Michael Grenier) (07/09/89)

From article <3299@copper.MDP.TEK.COM>, by byronl@copper.MDP.TEK.COM (Byron Lunz):
> In article <14978@ut-emx.UUCP> allred@ut-emx.UUCP (Kevin L. Allred) writes:
>>I had pointed out to me that 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
> 
> I received my new Gateway 2000 386/20 a few days ago.  It arrived with
> a Seagate ST296N and SCSI controller (not sure of the model #).  Transfer
> rate was one of my reasons for purchasing this system, and I was assured
> prior to the purchase by the salesperson that I could expect 800KB/sec.
> I was quite disappointed when both Spintest and Coretest 2.7 gave me
> data transfer rates of 440-460KB/sec!  Then, just today Mark Davis

What does Spintest actually test? Keep in mine that the drive has to 
physically seek and read the blocks into the scsi buffer on the drive
before transfer can begin again on the bus. If Spintest is measuring
the total time that it took for the request to get to the BIOS to the
time it took to get results back (as it must since Spintest doesn't
know the actual harware involved) then you are measuring the drive
delays as well as the SCSI bus transfer speed. If the drive could seek
and read the data in zero time then I'm sure you would see the much faster
SCSI transfer rates.

In a UNIX environment, scsi is a bigger win since the CPU can run another
process while waiting for the Seagate ST-01 controller to interrupt
up it to tell it that the transfer is ready to begin. 

Going to a fancier controller which supports DMA may speed up the
transfer rate but Spintest is still going to report a time slower
that the what an ESDI or RLL controller will do hooked to the same 
drive. For instance, using this Adaptec 2732 RLL 1:1 controller 
on this Maxtor drive (also a 28ms drive) I get over 800K bytes per
second transfer as reported by DOS based disk programs. 

A big plus for scsi is that it can make multiple disk requests at the
same time to different devices assuming you have a real operating
system, obviously not MSDOS, which can really speed up system
performance but with only one disk and a single tasking system the
closer you get to the disk head the better. 

    -Mike Grenier
    mike@cimcor.mn.org
    uunet!rosevax!cimcor!mike

davis@clocs.cs.unc.edu (Mark Davis) (07/09/89)

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)

ylo@sauna.HUT.FI (Tatu Yl|nen) (07/10/89)

In article <14978@ut-emx.UUCP> allred@ut-emx.UUCP (Kevin L. Allred) writes:
   I'm putting together a low end workstation for my personal use at home.
   It will have a 386SX, 4MB memory and monochrome VGA graphics.
   Initially I plan to just run MSDOS, but soon I would like to run UNIX.
   I currently am considering hard drives in the range of 65 to 80 MB.  I
   was only considering an RLL drive with 1:1 interleve controller until
   I had pointed out to me that 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
   addaptor works fine under DOS, but I have already had related to me
   that it probably won't work with UNIX because of lack of drivers (I
   heard that was a problem common to most SCSI boards even the expensive
   intelligent ones like the WD7000).  Are the various UNIX vendors
   developing drivers, so that I don't need to worry about this, or
   should I stick with the RLL controller and disks?

I have used a Priam 738 SCSI disk (337 MB, 20ms) with the Seagate
ST-01 controller for about one and a half years now.  For the first
half an year I used it under msdos in a slow 16-MHz 386 machine.
Coretest and others reported transfer rates in the range of 750 KB/sec.
(Check that you have the 0WS jumper installed - without it I only got
something like 500 KB/sec).

About an year ago I purchased Microport Unix System V/386, and wrote
a device driver for the controller and the disk.  I posted the driver
here about two weeks ago.  The driver has been in use on my system and
a couple of other systems for over an year.  The driver has proved to be
very reliable (some problems were reported with Seagate ST227N when
using 1KB sectors, but those disappeared by formatting the drive to
use 512 byte sectors).  The driver supports multiple drives and partitions.
My disk is partitioned in three partitions: 10 MB /tmp, 20 MB /u2 and
307 MB /u.  (BTW, I have never had any problems with large partitions.
Some people have reported problems in the news.)

I cannot give exact transfer rates under unix.  With my original driver
I only got something like 160 KB/sec while reading a large (10-20 MB)
file with dd -bs 64k.  That with an interleave of 9 and 1 KB sectors (sic!).
I have since optimized the data transfer routines by writing them
in assembly language.  This should probably allow interleaves in the
range 1-3.  I have not yet been able to test any other interleaves, as I have
not wanted to reformat the entire disk (it takes quite a while to copy
300 megabytes to floppies and back...)  Note that when formatting the disk,
it can be helpful to explicitly specify that mkfs does no interleaving
on the file system level as that is already handled by the drive.

As a reference, measured the same way my 40ms 42MB MFM drive gives 
40 kB/sec (sic!).  I was not able to improve it from that.
The scsi disk was actually so much faster that I copied /bin and /usr/bin
to the scsi disk (/u/bin & /u/usr/bin) and put those in PATH before
/bin and /usr/bin.  The difference is very significant.

The biggest problem with the driver is that during heavy disk activity
the serial lines lose incoming characters.  But then I hear this is a
general problem with Microport...

BTW, my driver cannot be used to boot from the scsi disk.  I use the
42 MB disk that came with the system for booting and swap (luckily I have
10 MB of ram, so the machine hardly ever swaps).


    Tatu Ylonen      ylo@sauna.hut.fi

allred@ut-emx.UUCP (Kevin L. Allred) (07/11/89)

In article <14978@ut-emx.UUCP>, allred@ut-emx.UUCP (Kevin L. Allred) writes:
> I had pointed out to me that 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

My questions seem to have raised a bit of interest and varied reaction
from several respondents.  In brief the key points of the responces
have been (focussing on the ST01 or ST02 rather than the ST296N):

1)  Spintest and Coretest recorded transfer rates of about 450 KB/sec.
2)  Spintest may not fairly report SCSI speeds (huh?).
3)  BIOS can make a big difference -- >800 KB/sec for 3rd party BIOS.
4)  Jumpering on the controller makes a difference (XT vs AT?)
    transfer rates jumped from 500KB/sec to 750KB/sec.
5)  ST01 and ST02 do not support DMA transfers.  Under Unix (DOS?)
    simultanious disk I/O with serial transfers can loose characters.

Is anyone familiar enough with the ST0x controller to respond about
the true capabilities of the ST0x controllers -- Seagate are you
listening?  If anyone can forward this on to some one there it would
be appreciated.

Item 5 in the list above is the current biggest concern to me.  If the
ST0x is not a DMA device what happens when I try to run software like
zmodem downloads that want to do serial and disk I/O simultaneously?

By the way, how can I get Spintest or Coretest?  I would like to get a
copy to benchmark whatever combination of disk and controller I end up
buying?
-- 

	Kevin Allred
	allred@emx.cc.utexas.edu
	allred@ut-emx.UUCP

km@cadre.dsl.PITTSBURGH.EDU (Ken Mitchum) (07/11/89)

>Item 5 in the list above is the current biggest concern to me.  If the
>ST0x is not a DMA device what happens when I try to run software like
>zmodem downloads that want to do serial and disk I/O simultaneously?

The ST01 does support interrupts, so there is no need for the processor
to "wait" for a transfer to take place. DMA was probably left off the
card 1) to save money and 2) because there is no effective way in a DOS
environment to take advantage of it.

 Ken Mitchum
 km@cadre.dsl.pitt.edu

paula@bcsaic.UUCP (Paul Allen) (07/11/89)

Is there anyone in the Pacific Northwest (or the West 
Coast, or... :-) who saved the Seagate ST-01 SCSI driver 
posted by ylo@sauna.hut.fi a couple of weeks ago?  I'm 
considering buying a machine with this SCSI adaptor and 
could use an example driver as I create a driver for 
Minix.  If you have the driver and can mail it to me, 
please drop me a note.

On another note, I'm seeing reports (and rumors) placing
the 'Coretest' transfer rate of systems using Seagate
SCSI adaptors anywhere from 340 to 800 Kb/sec.  Tatu
Yl|nen reported that inserting the 'Ows' jumper raised
the transfer rate from 500 to 700 Kb/sec.  Anybody else
have any stories to tell?  

Paul

-- 
------------------------------------------------------------------------
Paul L. Allen                       | pallen@atc.boeing.com
Boeing Advanced Technology Center   | ...!uw-beaver!bcsaic!pallen

Ralf.Brown@B.GP.CS.CMU.EDU (07/11/89)

In article <2966@cadre.dsl.PITTSBURGH.EDU>, km@cadre.dsl.PITTSBURGH.EDU (Ken Mitchum) writes:
}>Item 5 in the list above is the current biggest concern to me.  If the
}>ST0x is not a DMA device what happens when I try to run software like
}>zmodem downloads that want to do serial and disk I/O simultaneously?
}
}The ST01 does support interrupts, so there is no need for the processor
}to "wait" for a transfer to take place. DMA was probably left off the
}card 1) to save money and 2) because there is no effective way in a DOS
}environment to take advantage of it.

Another reason for leaving off the DMA is that DMA is a big lose on AT-class
or 386 machines (at least as implemented by IBM PC compatibles--1 microsecond
per transfer, as opposed to 400 ns on even a 10/0 AT using programmed I/O
with the INSW and OUTSW instructions).  In addition to being slower than
INSW/OUTSW, DMA on a PC-compatible suffers from the problem of not being able
to cross 64K boundaries, which INSW/OUTSW have no problems with (though they
are, of course, limited to at most 64K at one time).

With a true multitasking OS, however, even slow DMA would be better than
programmed I/O, since another process can run while the transfer takes place.
 
--
UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=- Voice: (412) 268-3053 (school)
ARPA: ralf@cs.cmu.edu  BIT: ralf%cs.cmu.edu@CMUCCVMA  FIDO: Ralf Brown 1:129/46
			Disclaimer? I claimed something?
"When things start going your way, it's usually because you stopped going the
 wrong way down a one-way street."

newman@inco.UUCP (Bo Newman) (07/11/89)

As to the Seagate SCSI Controler/Drives, I got one from Megahaus in TX for
my Tandy 1000TL  (48MB)  and had problems with it "falling asleep" before it
could complete a transfer of any size.  I have been told that these controlers
are not 100% *bus friendly* on all systems.  I have since gone bask to more
generic drives.  Good Luck!


===================================================================
:Bo Newman	 newman@inco.uu.net	      uunet!inco!newman	  : 
:McDonnell Douglas Electronics Systems Company (MDESC-WDC)	  :
:McLean Virginia						  :
:Voice Mail USA (202) 898-5564 (Answers as "The Newman Group")    :
:Fax USA (703) 883-3889	         				  :
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dkt@sequent.UUCP (Doug Thompson) (07/12/89)

In article <12949@bcsaic.UUCP> paula@bcsaic.UUCP (Paul Allen) writes:
>Is there anyone in the Pacific Northwest (or the West 
>Coast, or... :-) who saved the Seagate ST-01 SCSI driver 
>posted by ylo@sauna.hut.fi a couple of weeks ago?  I'm 
>considering buying a machine with this SCSI adaptor and 
>could use an example driver as I create a driver for 
>Minix.  If you have the driver and can mail it to me, 
>please drop me a note.

I am new to this group, and thus also missed the Driver for th ST01
and am also interested in getting a copy.
Thanks

buck@siswat.UUCP (A. Lester Buck) (07/13/89)

In article <2966@cadre.dsl.PITTSBURGH.EDU>, km@cadre.dsl.PITTSBURGH.EDU (Ken Mitchum) writes:
> >Item 5 in the list above is the current biggest concern to me.  If the
> >ST0x is not a DMA device what happens when I try to run software like
> >zmodem downloads that want to do serial and disk I/O simultaneously?
> 
> The ST01 does support interrupts, so there is no need for the processor
> to "wait" for a transfer to take place. DMA was probably left off the
> card 1) to save money and 2) because there is no effective way in a DOS
> environment to take advantage of it.
> 
>  Ken Mitchum
>  km@cadre.dsl.pitt.edu

The ST01 supports an interrupt on exactly one condition, the assertion of
the SCSI SEL signal.  For the ST01 this means it is being reselected to
continue a transfer that the target (e.g., disk) previously suspended.  [It
also might mean that the ST01 is being selected as a target by another
initiator, but the VLSI protocol chip on the ST01 does not support the
inverse REQ/ACK sequence required for this mode.]  But during a transfer,
the ST01 definitely has a problem.  It is designed to allow a REP MOVSB
string move between the data buffer and the SCSI data port, for an efficient
CPU transfer at full bus bandwidth.  Unfortunately, the target runs
everything in the transfer, and can change the SCSI bus phase from data
in/out to anything, including bus free, whenever it likes.  It will do this
for unusual events like parity errors, or extremely common events like
variable length tape records when the actual length is less than the
requested length.  Unless you are SURE that the bus phase will never change
during the REP MOVSB (say, a block device with no errors), and thereby read
some SCSI message and status bytes into a user buffer (or worse, time out
and wake up in the bus free phase!), you need to monitor for bus phase
changes before every byte, which severely limits the tranfser rate.  The
ST01 disk driver for Microport recently posted calls these the "fast" and
"slow" modes, and it seems the "fast" mode is reasonably reliable for disks.
The ST01 also violates the SCSI standard in a minor way that again will
probably not ever show up in normal use.

Basically, the ST01 is a terrifically cost effective SCSI host adapter for
cheaper implementations.  But you would be crazy to spend thousands on a
fast, synchronous SCSI disk and hook it to a $50 asynchronous ST01 when only
$250 more will get you an Adaptec 1542A with synchronous transfers and first
party DMA.


-- 
A. Lester Buck		...!texbell!moray!siswat!buck

john@foil.UUCP (John Cavanaugh) (07/13/89)

>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.  It arrived with
>>a Seagate ST296N and SCSI controller (not sure of the model #).
>>Spintest and Coretest 2.7 gave me data transfer rates of 440-460KB/sec!
>>
>>If someone out there is 
>>actually seeing transfer rates around or over 800KB/sec, I'd sure
>>like to hear about it.
>>

So would I.  Last night I installed a ST02 ST296N in my Dell System 200
(286/12.5) and was suprised to see that my ST251-0 was constantly clocking
faster access times than the SCSI.  Using Coretest 2.7, I was getting
somewhere around 28-29ms for the 251 [who knows, maybe the people at Dell
were confused and gave me the 251-1...] and about 32-33ms for the 296.
I also got about 440KB/sec data transfer rate.  Strange.

The one thing that I thought might be the holdup was the 8-bit card (ST02)
that I installed with the drive.  Does Seagate make a 16-bit SCSI adaptor?

--  
John Cavanaugh - via GT<->Usenet Test System - Portland, Oregon 
UUCP: ...!tektronix!tessi!agora!foil!john  --  GT Net/Node: 056/002 

mms00786@uxa.cso.uiuc.edu (07/16/89)

/* Written 10:47 pm  Jul 12, 1989 by john@foil.UUCP in uxa.cso.uiuc.edu:comp.sys.ibm.pc */

>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.  It arrived with
>>a Seagate ST296N and SCSI controller (not sure of the model #).
>>Spintest and Coretest 2.7 gave me data transfer rates of 440-460KB/sec!
>>
>>If someone out there is 
>>actually seeing transfer rates around or over 800KB/sec, I'd sure
>>like to hear about it.
>>

So would I.  Last night I installed a ST02 ST296N in my Dell System 200
(286/12.5) and was suprised to see that my ST251-0 was constantly clocking
faster access times than the SCSI.  Using Coretest 2.7, I was getting
somewhere around 28-29ms for the 251 [who knows, maybe the people at Dell
were confused and gave me the 251-1...] and about 32-33ms for the 296.
I also got about 440KB/sec data transfer rate.  Strange.

The one thing that I thought might be the holdup was the 8-bit card (ST02)
that I installed with the drive.  Does Seagate make a 16-bit SCSI adaptor?

--  
John Cavanaugh - via GT<->Usenet Test System - Portland, Oregon 
UUCP: ...!tektronix!tessi!agora!foil!john  --  GT Net/Node: 056/002 
/* End of text from uxa.cso.uiuc.edu:comp.sys.ibm.pc */

William.Cummins@bigtime.fidonet.org (William Cummins) (07/21/89)

I also have the same card drive combination and I get about 567kb trans 
-fer but I don't know why the card is rated to go up to 1mbs but aas 
you know we don't get that mutch don't waste your time calling Seagate 
ether thay will just say it is something wrong with the sync. between 
your computer and the card  Idea being that your computer is the blame 
can't take the data that fast (Shure a 20mhz 386 isn't fast enough!) 
any way the drive seems to work well dispite that. and no seagate 
dasn't have a 16 bit card  but you can get one but spendy$$$  from 
other manufactures and I don't know if theay have he drivers for the 
drive ether i don't know if the drive even uses the STANDARD scsi 
interface.  I also wonder why the drive scans the disk every few 
minutes ether but givin the above the drive seems to work great
     william cummins 
--  
William Cummins
Domain: William.Cummins@bigtime.fidonet.org
UUCP: ...!{tektronix, hplabs!hp-pcd}!orstcs!bigtime!William.Cummins
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richard@uhccux.uhcc.hawaii.edu (Richard Foulk) (07/31/89)

In article <6100003@adaptex> neese@adaptex.UUCP writes:
} 
} If you choose to use the Adaptec AHA-1540 SCSI host adapter, support
} for this board is already included in SCO 2.3GT and ISC 2.0.  This
} adapter in combination with a Quantum Pro80 will yeild a data rate
} of about 2.8MBytes/sec under DOS and is one of the fastest combinations
} for Unix.
} 
} 
} 			Roy Neese
} 			Adaptec Central Field Applications Engineer
} 			UUCP @ {merch,texbell,killer}!cpe!adaptex!neese

[Unfortunately various mail attemps have failed.  So...]

I have additional questions perhaps you could help me with.

	1. Does Bell-Tech Unix have support for this board yet?
		I haven't bought it yet, but Bell-Tech looks like
		the best performer in the i/o through-put realm.
	2. Any recommendations on 300 and 600 meg drives that would
		work well with this card?
	3. How does it do with multiple drives?
	4. Where can I buy one?

Thanks.

Richard Foulk			richard@uhccux.uhcc.hawaii.edu
University of Hawaii
1993 East-West Rd.
Honolulu, HI  96822
(808) 735-5013

neese@adaptex.UUCP (08/03/89)

>I have additional questions perhaps you could help me with.
>
>	1. Does Bell-Tech Unix have support for this board yet?
>		I haven't bought it yet, but Bell-Tech looks like
>		the best performer in the i/o through-put realm.

I don't know if Bell Tech has support for it.

>	2. Any recommendations on 300 and 600 meg drives that would
>		work well with this card?

My preference is either CDC or Maxtor.  Both have proven to be high quality,
high performance products.  But I don't know of any HD's that won't work with
the card.

>	3. How does it do with multiple drives?

The more drives the better.  In benchmarking, 2 drives doubles throughput
if the file systems are both being accessed and 3 drives triples and
so on and so forth.

>	4. Where can I buy one?

Of all the distributors for the product, Tandy has the lowest price.


			Roy Neese
			Adaptec Central Field Applications Engineer
			UUCP @ {merch,texbell,killer}!cpe!adaptex!neese

pim@ctisbv.UUCP (Pim Zandbergen) (08/05/89)

neese@adaptex.UUCP writes: (about the Adaptec SCSI host adaptor)

>>	4. Where can I buy one?

>Of all the distributors for the product, Tandy has the lowest price.

OK, here are my questions:

Is the Tandy SCSI host adaptor equivalent to the Adaptec AHA-1540,
the AHA-1540A, or the AHA-1542A. Tandy could not tell me this.

What does scatter-gather mean for performance (the 1540 vs the 1540A)?


PS, I would have mailed this question, if only adaptex was really
registered to the uucp domain.
-- 
--------------------+----------------------+-----------------------------------
Pim Zandbergen      | phone: +31 70 542302 | CTI Software BV
pim@ctisbv.UUCP     | fax  : +31 70 512837 | Laan Copes van Cattenburch 70
...!uunet!mcvax!hp4nl!ctisbv!pim           | 2585 GD The Hague, The Netherlands

neese@adaptex.UUCP (08/07/89)

The Tandy SCSI host adapter is the same as the AHA-1540A, except for
the BIOS.  The Tandy BIOS has some features built in that take advantage
of the hardware in the Tandy system, but if you put it in a non-Tandy
box it won't attempt to use those features.
Scatter/gather has to be implemented in the OS for it to be used.


			Roy Neese
			Adaptec Central Field Applications Engineer
			UUCP @ {merch,texbell,killer}!cpe!adaptex!neese