[1612] in linux-scsi channel archive
Re: Which pci-scsi host adapter should I get?
daemon@ATHENA.MIT.EDU (Gerard Roudier)
Tue Mar 25 17:28:37 1997
Date: Tue, 25 Mar 1997 22:54:36 +0000 (GMT)
From: Gerard Roudier <groudier@club-internet.fr>
To: "art s. kagel IFMX x2697" <kagel@dg1.bloomberg.com>
cc: Robert Johannes <rjohanne@piper.hamline.edu>,
Edward Welbon <welbon@bga.com>, linux-scsi@vger.rutgers.edu
In-Reply-To: <Pine.D-G.3.91.970324084201.1689B-100000@dg1>
On Mon, 24 Mar 1997, art s. kagel IFMX x2697 wrote:
> Art S. Kagel, kagel@ts1.bloomberg.com
>
> On Fri, 21 Mar 1997, Gerard Roudier wrote:
>
> > On Fri, 21 Mar 1997, art s. kagel IFMX x2697 wrote:
> >
> > > Linux supports most major SCSI controllers SCSI-I -> SCSI-III Fast/Wide.
> > > I have had Future Domain (RIP), NCR, and BusLogic and I have found the
> > > BusLogic PCI SCSI-III Fast/Wide Bus Master controller to be extremely
> > > fast and reliable. (My FD was ISA bus and Very slow as expected. The
> > > NCR was PCI and apparently had a bad trace so I returned it and replaced
> > > it with the BusLogic.)
> >
> > If you just mean that oranges are not apples, I agree.
>
> No I just mean that I have had three different, Linux supported, SCSI
> cards and that I like the BusLogic best.
I don't care about what you like or dislike.
Seemed to me you were claiming Buslogic was gold and NCR was just sh*t.
Being given that you did not write the reasons of your opinion, I just
asked you be more accurate.
> > - Which Future domain board?
>
> I do not remember the model # but it was an ISA card with narrow SCSI-II
> support. It actually worked fine with both DOS and Linux but when I
> upgraded from my ISA 386-40 motherboard to a PCI Cyrix-P166 mother board
> I wanted a faster PCI card. The FD was slower than either the NCR or the
> BusLogic simply because it was constrained by the ISA bus.
If you compare a ISA 386-40 system to a PCI Cyrix-P166+, you are comparing
oranges to apples. You are too comparing oranges to apples when you
compare and ISA SCSI-II board with a Fast40 PCI SCSI controller.
> > - Which NCR board?
>
> It was a Tyan 1365 board with an NCR 825 SCSI chip and Bios. The card was
> PCI SCSI-II Fast/Wide. The Bus Logic is a BL-958 Fast-Wide Ultra
> SCSI-III PCI Bus Master card.
The Tyan 1365 is a fast wide SCSI-II board.
Did you use it with wide scsi disks at 20 MB/sec sync transfers and all
SCSI features enabled?
Have you some *real* results?
[ problems of disk geometry snipped ]
> > - What mean 'fast' for you?
>
> I did some informal I/O benchmarks on the after noticing a subjective
> improvement going from the NCR to the BusLogic card. Anything I/O
> intensive seemed to run 15-40% faster. Again I had no formal timings
> from when the NCR had been installed so these are somewhat subjective but
> I know how long a long compile took and how much finger tapping I did, so...
I think I guess what happened.
Could it be possible that you used the NCR in narrow mode with wide disks,
asynchronous transfer, etc.. and the bus Logic with all SCSI features
enabled?
> > - What means 'bad trace'? (I did not find this expression in my dictionnary)
>
> When the NCR card was installed and the machine was on for more than a
> few hours, the machine would hang on any command which accessed the
> drives. In other words I could run command.com or bash built in
> commands and even sometimes list directories that had been in cache
> already but when I tried to load an executable or list a directory not
> read before the machine would hang. In this case rebooting caused the
> machine to hang again in the middle of printing the NCR BIOS copyright
> header. 'Bad trace' means that apparently one of the printed circuit
> trace lines, or one of the solder connections was cracked or 'cold' (a
> term refering to a solder joint in which one of the parts being joined
> was not sufficiently heated to permit a good electrical connection,
> producing a joint whose electrical properties depend upon temperature).
> In other words the card stopped working when it became too hot (though
> the components are properly cooled).
I have used a TYAN 1565 during 6 months and do lots of load tests with
it and never have had any problems. Performances were great with my
Atlas I Wide.
My guess could be that the terminations of the board were perhaps
missconfigured due to a known error in the TYAN documentation.
(Or your SCSI bus was not correct).
In any case, if the TYAN Board worked as you described, the problem
should be well-known and I never heard such a problem except from you.
> > - What means 'driver compatible' for you?
>
> Leonard Zubkoff, who maintains the drivers for BusLogic support in Linux
> reports, if I understand correctly, that all BusLogic controllers
> essentially use the same driver code. He only had to add code recently
> for the FlashPoint line which does not have an imbedded processor and
> depends on the driver for several functions that are on-board on the
> other BL controllers. The extra code you see below is for the
> FlashPoint line to replace the on-board functions with driver based
> functions. The FlashPoint series is much less expensive than the other BL
> controllers because of the lack of an on-board CPU and this accounts for
> the extra code. The basic BusLogic driver is slightly smaller than the
> aic7xxx driver and much smaller than the ncr53c8xx driver.
The aic7xxx driver as well as the ncr53c8xx support an entire family of
SCSI controllers. Such drivers are quite comparable to Leonard's
excellent driver on this point.
The extra code for the Flashpoint is about 300k. So, people who are using
a Flashpoint currently use a driver that is 500k source code. That's
about half the size of some first Linux versions severall years ago.
BusLogic controllers use a general purpose CPU and is what is called
and "intelligent" controller. ncr53c8xx controllers use a special
pci/scsi risk processor which forces to do most of scsi stuff in the
O/S driver. That is the reason a BusLogic driver is generally
shorter that a ncr53c8xx one. (Same for aic7xx against BusLogic).
Gerard.
(Sorry for the bandwitch)
