Tyan Thunder+SCSI nightmare

[T. Horsnell]

Hi all,
I have a big problem with my Tyan Thunder K8S Pro S2882
dual-Opteron board and I wonder if you can help.

I'm running FC3, kernel 2.6.10 smp.

I've reduced my system to a boot disk attached to the
on-board SCSI, and no other disks.

If I plug extra Adaptec 39320 SCSI adapters into the
PCI-X bus I get large numbers of assorted PCI errors
logged (like PCI Interrupt Error), when I access
the SCSI disk with commands like
'dd if=/dev/sda of=/dev/null bs=65536'.

If I remove any one of the extra adapters, the problem
reduces.
If I remove any two of the extra adapters, the problem
goes away.

I've tried using the single-processor kernel version,
and I've tried booting from a Knoppix 3.6 CD (2.4.27 i386 kernel)
but the problem still occurs, although to a much less extent.

The Tyan support FAQ indicates that a PCI-X interrupt routing
problem was fixed at BIOS 2.03, and my BIOS version is 2.03.
I've also tried disabling the Adaptec INIT13 in the non-boot
adapters and the PCI-VGA interrupt on the Tyan BIOS, but the
problem remains.

I'm contacting my vendor and Tyan, but in the meantime
any ideas anyone? Has anyone seen this before?

Cheers,
Terry.