SMP issues on K8S Pro S2882G3NR

James R. Van Artsalen james at
Sat Apr 3 12:49:17 PST 2004

Cassidy B. Larson wrote:

>One more question I had.
>What's the typical temperature of two 246 opterons?  We have it in a 1U box
>with fans and ventilation galore, but when I push the box for more then 20
>seconds with 0 CPU free, it freezes.  A quick power cycle into the BIOS
>details that I'm running at over 95 degrees centigrade.  Letting it cool
>down will let me run my CPU test another 2-3 times then freezes again.

The rated case temperature is 70 C.

There is a hardware-enforced shutdown mechanism at "125 C" but I don't 
know where this is measured.

I don't know if the ROM Setup number is accurate, or what it is 
measuring.  I have no confidence in this number.  There are two pins to 
an on-die thermal diode they could monitor, but I don't know how to 
relate this value to the rated thermal maximums.

>I looked through the Tyan manual and found nothing of the halt temperature,
>nor AMD's site.

, the AMD Opteron Processor Data Sheet, the Power Management sections 
and the Miscellaneous Pin Descriptions for THERMDA, THERMDC and THERMTRIP_L.

>If needs be I may send this back and get a 2U case with better cooling.

Make sure CPU cooler exhaust air is not recirculating back into the CPU 
cooler air intake.

Most ATX thermal schemes are completely incompetent, as is the BTX 
proposal.  The focus should be on getting hot exhaust air out of the 
chassis before it heats any component, especially the CPU.  If you have 
to get another case evaluate thermals by seeing how they evacuate hot 
exhaust from the CPU (it should not recirculate or bake any other 

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