1 - Select 20 MHz synchronous data transfers under linux config and
make the kernel.
2 - Boot the kernel with the following lilo boot setup command:
lilo> linux root=etc... ncr53c8xx=sync:12
3 - After boot up, ask the driver to renegotiate Fast-20 for the target:
echo "setsync 0 12" >/proc/scsi/ncr53c8xx/0
(12 means 50ns transfer period = 20 Mega transfer/sec = 40 MB/sec for
wide 16)
If you read this mail under Linux, just enter (3), do some disk IOs and
have a look at you syslog (if you system is still working :) ).
See linux/drivers/scsi/README.ncr53c8xx for detailed informations.
Gerard.
On Wed, 25 Mar 1998, Mark Lehrer wrote:
>
> Hello!
>
> I almost hate to put this on the linux-kernel list, but the newsgroups
> were of literally no help...
>
> I have an NCR/Symbios 875 UW scsi controller and Cheetah 4GB hard
> disk. I also have a 3GB UDMA drive (WD 33200). The UDMA is / and
> the Cheetah is /home. This system is primarily a web server.
>
> I am disappointed in what Bonnie has to say about performance... it
> claims that the UDMA edges out the Cheetah.
>
> Below are the boot messages: it claims at the end that it is running
> "SLOW WIDE" instead of fast-20... that might be the entire problem. The
> controller comes up and says fast-20 and this is the only device on the
> chain so I can't blame it on an old device sharing the bus.
>
> My question: is anyone else running this configuration? What can I do
> to get performance up to where it should be? Does the "syncronous
> transfers" section in the kernel config cause this or is it more likely
> to be a jumper setting on the drive?
>
> I have the drive on the very end of the SCSI cable; could that make a
> difference?
>
> Thanks,
> Mark
>
>
> -- snip, snip --
>
> ncr53c8xx: at PCI bus 0, device 10, function 0
> ncr53c8xx: 53c875 detected
> ncr53c875-0: rev=0x03, base=0xe5800000, io_port=0xb800, irq=10
> ncr53c875-0: ID 7, Fast-20, Parity Checking
> ncr53c875-0: on-board RAM at 0xe5000000
> ncr53c875-0: restart (scsi reset).
> ncr53c875-0: copying script fragments into the on-board RAM ...
> scsi0 : ncr53c8xx - revision 2.4a
> scsi : 1 host.
> ncr53c875-0-<0,0>: using tagged command queueing, up to 4 cmds/lun
> Vendor: SEAGATE Model: ST34501W Rev: 0018
> Type: Direct-Access ANSI SCSI revision: 02
> Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
> scsi : detected 1 SCSI disk total.
> ncr53c875-0-<0,0>: SLOW WIDE SCSI 10.0 MB/s (200 ns, offset 15)
> SCSI device sda: hdwr sector= 512 bytes. Sectors= 8887200 [4339 MB] [4.3 GB]
>
> --------
>
> Kernel config NCR section:
>
> NCR53C8XX SCSI support (CONFIG_SCSI_NCR53C8XX) [Y/n/?]
> detect and read serial NVRAMs (CONFIG_SCSI_NCR53C8XX_NVRAM_DETECT) [N/y/?]
> enable tagged command queueing (CONFIG_SCSI_NCR53C8XX_TAGGED_QUEUE) [Y/n/?]
> use normal IO (CONFIG_SCSI_NCR53C8XX_IOMAPPED) [N/y/?]
> maximum number of queued commands (CONFIG_SCSI_NCR53C8XX_MAX_TAGS) [4]
> synchronous transfers frequency in MHz (CONFIG_SCSI_NCR53C8XX_SYNC) [5]
>
>
>
>
>
>
>
>
>
> -
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