Very Computer

I recently upgraded to a new PCI motherboard, and I am debating retiring
my Adaptec 1452B SCSI card for a PCI card. What is now the recommended
card? My motherboard BIOS will support either the NCR53C810 or the
Adaptec 7850. I am currently running Debian 1.1, if that makes any
difference.

I have heard the NCR53C810 is a very good, low cost board, but the
hardware HOWTO also says that it doesn't support disconnect. I looked
at the latest kernel source, and I now see there are 2 drivers for the
810 (53c7,8xx and ncr53c8xx), both of which look like they support
disconnect, so which should be used if I do get the 810?

Thanks for any replies, either posted or emailed.

PS.  Is there a WWW site which has collected hardware info such as this?

--

[Carl Johnson]

|   I have heard the NCR53C810 is a very good, low cost board,

Absolutely correct.

|   but the
|   hardware HOWTO also says that it doesn't support disconnect.

The hardware itself certainly supports disconnect. Whether this is used by
the driver is another matter. The FreeBSD driver certainly uses it.

|   PS.  Is there a WWW site which has collected hardware info such as this?

There is some 53c810 info (not Linux-specific) at

        http://www.nethelp.no/scsi/ncrbios.html

: I recently upgraded to a new PCI motherboard, and I am debating retiring
: my Adaptec 1452B SCSI card for a PCI card. What is now the recommended
: card? My motherboard BIOS will support either the NCR53C810 or the
: Adaptec 7850. I am currently running Debian 1.1, if that makes any
: difference.

The Tyan Yorktown uses the ncr53c825. I've seen it being offered
for $95.

Edward

Quote:> What is now the recommended
> card? My motherboard BIOS will support either the NCR53C810 or the
> Adaptec 7850. I am currently running Debian 1.1, if that makes any
> difference.

> I have heard the NCR53C810 is a very good, low cost board, but the
> hardware HOWTO also says that it doesn't support disconnect. I looked
> at the latest kernel source, and I now see there are 2 drivers for the
> 810 (53c7,8xx and ncr53c8xx), both of which look like they support
> disconnect, so which should be used if I do get the 810?

My advice is go for a ncr card but fast scsi2 seems a bit slow if you
use more than 3/4 modern scsi hard disks and/or raid0. fast scsi2 is
only 10 MB/s.

I think a better choice would be a fast wide (20MB/s) or ultrawide
(40MB/s) card. wide cards are supported by the drivers (ncr53c8xx) but
not ultra wide :

from the ncr53c8xx readme
------------------------------------------------------------------------------
2. Supported chips and SCSI features

The following features are supported for all chips:

        Synchronous negotiation
        Disconnection
        Tagged command queuing
        Scsi parity checking
        Master parity checking

"Wide negotiation" is supported for chips that allow it.
The following table shows some characteristics of NCR 8xx family chips:

       On board                        Supported by    Tested with
Chip   SDMS BIOS   Wide   Ultra Scsi   the driver      the driver
----   ---------   ----   ----------   ------------    -----------
810        N         N        N            Y             Y
810A       N         N        N            Y             Y
815        Y         N        N            Y             Y
825        Y         Y        N            Y             Y
825A       Y         Y        N            Y             Not yet
875        Y         Y        Y(1)         Y             Not yet

(1) Ultra scsi extensions will be supported in a future release of the
    driver.
------------------------------------------------------------------------------

tyan sell a cheap fast wide controler. It must be a good choice.

If you want to go for a ncr53c810 card, don't buy the ga-410, it
doesn't have active termination.

I don't know cards which use ncr53c875.

Pascal

Quote:>PS.  Is there a WWW site which has collected hardware info such as this?

Cheers, Michael Will

I swear by BusLogic cards (I have a 545, a 542, several 445s, several
946s, and one solitary 948) and recommend them exclusively to customers.
Other people will be equally fanatical about the NCR boards (which are,
I have to admit, very nice; I have one non buslogic machine that uses a
single NCR to drive a CD burner as well as a system disk and a spool
disk, and the footprint of the NCR/AT&T/Symbios DOS drivers cannot be
beat if you're also planning on running DOS on the machine), the Adaptec
2940, or any of the other PCI cards supported in Linux.

                 ____

                  \/

|> I have heard the NCR53C810 is a very good, low cost board, but the
|> hardware HOWTO also says that it doesn't support disconnect. I looked
|> at the latest kernel source, and I now see there are 2 drivers for the
|> 810 (53c7,8xx and ncr53c8xx), both of which look like they support
|> disconnect, so which should be used if I do get the 810?

At least as of Linux 2.0.0, disconnects are supported and work well with my
system. Last night I ran full dump to my Archive Viper 2525, played a CD on my
Toshiba XM3501TA, and ran a find / on my Conner CFP1080S disk just for fun,
with no problems at all.
--

John Swensen