1. Many motherboards were shipped with defective COAST (cache) modules, these tend to work fine when the system is lightly loaded but when a second CPU is started data gets corrupted. To determine if this is your problem, remove the COAST module from the motherboard (physically), it is not sufficient to disable the 2nd level cache in the BIOS.
2. Some motherboards are very sensitive to the placement of cards on the ISA bus (which slots particular peripherals are plugged into); shuffling ISA cards around sometimes helps matters.
3. Some motherboards will not reliably run at the CPU's rated speed in a dual processor configuration; sometimes lowering the CPU speed helps this situation (ie: if you have a P200 attempt to run it at 166Mhz).
4. The 2nd IDE port built into the motherboard will not work on some machines (depends on BIOS revision, newer ones are broken) with a single ATAPI CDROM drive (the drive is not detected at boot time). If an IDE hard drive is attached as master on the second port, both it and the slave ATAPI CDROM will operate in uniprocessor mode.
5. The 2nd IDE port built into the motherboard will not work on any machine tested in multiprocessor mode; Tyan ommitted a connection from the 2nd IDE port interrupt pin to the I/O APIC (which is only used in MP mode). This can be worked around by adding the following to /etc/mp.config:

        noextclk
        irq15=ext
        irq0=ext

   when running in this mode performance is degraded since interrupts from the system clock and the 2nd IDE channel are all directed to the boot processor (instead of the 'best' processor).
   Another option to solve this problem (for hardware hackers) is to manually run a jumper wire between the interrupt pin on the 2nd IDE connector (pin 31) and the IRQ15 pin on an available ISA connector (pin D06); this also fixes the problem of not seeing a lone ATAPI drive on the 2nd port at boot time.
   A final option is to disable the onboard 2nd IDE port and use an ISA add-in card.
6. Older Award BIOSes are not Intel MPS compliant and provide incorrect interrupt routing information to the kernel; solution: flash a more up to date BIOS from the Tyan web site.

Issues:

1. When running both CPU's the motherboard is *much* more sensitive to memory timing; SIMM's that worked OK in UP mode may not work correctly with both CPU's running. Turning off 'chipset special features' in the BIOS sometimes helps, as does running the CPU's slower than their rated speed.
2. The presence of a Creative SB16 (or, mostly likely, clones) on the ISA bus will sometimes cause erratic behavior. It is not neccesary to have the sound drivers loaded to see problems. Sometimes putting the SB16 in a different slot will help. This problem has not been reported with AWE64's, but we have no reason to believe an AWE64 will work better either.

     extclk

	irqN=2,N,level,low

There are some additional notes regarding SCSI support on this box:
The AIC7860 (ultra-narrow) on the motherboard runs with 4.0 drivers.
The AIC7890 (ultra2-wide) isn't currently supported. The driver for this device will be available sometime in the future.
The AMI Mega-Raid controller on this board is not supported by drivers in the 4.0 release. The driver for this device will be available sometime in the future.

Watch this space for the latest status.