system overheating, broken acpi

[DrChuck]

I just built an AMD 64 X2 dual-core system with the Asus A8N-VM motherboard, which powers itself down under after running at full load (100% cpu on both cores) for about 20-30 minutes. The case has a single 80mm fan, no extra cards installed, and the air blowing out does not seem hot at all. I assume the powerdown means the cpu is overheating, but I can't know for sure, as ACPI does not function correctly. I'm running Fedora 4, 2.6.17 SMP kernel, which has acpi compiled in. In /proc/acpi, the only directories with entries are "button" and "processor", but the thermal_zone directory is empty. The bios seems to be fully aware of the cpu temperature (35 degC or so at idle) and fan speeds, and based on the control options, it should be able to vary the fan speed in response to the temperature.

I think there may be 2 separate problems here, the overheating and the broken acpi, and I'm not sure where to begin, but here are some questions which come to mind:
1) Has anyone, with any kernel compile or distro, gotten acpi to work with the A8N-VM? or any socket 939 motherboard?
2) Is this possibly an SMP kernel problem - I also have a dual Xeon system running FC4, with empty /proc/acpi directories, while 2 other single-core systems (one laptop, one desktop) function correctly.
3) Which has the final say in cpu thermal control - the kernel or the bios? Can a malfunctioning acpi interfere with the bios and cause the overheating? Should I completely disable acpi at boot time, with "acpi=off", and let the bios control take over?
5) Is this simply a lack of sufficient cooling, and not a fan control problem at all?

Thanks in advance for your advice,
drChuck

[dkeav]

1 make sure you have the latest bios for that motherboard
2 make sure you didnt apply too little or too much thermal paste, a thin film over the entire surface of that chip is adequate it should not be overly thick though
3 are you using the stock cooler, or did you purchase and OEM chip and possibly using a cooler that is not rated for that processor, if so you might want to get a better cooler or possibly a water cooling system

[DrChuck]

Dkeav,
Thanks for your response. Yes, I have the latest bios from Asus. I'm using the stock cooler from the retail kit, and the dual core processor seems to draw less power than my Athlon 2800+. I measured the mains current at full load, and the entire system draws about 1 Amp ( at 120 VAC ). So I'm really surprised to see any cooling issues at all. In the end I may try a beefier cooler

But how do I monitor the cpu temperature? To reiterate my first point in the OP:
1) Has anyone, with any kernel compile or distro, gotten acpi to work with the A8N-VM? or any socket 939 motherboard? Or any AMD dual core processor? It would be helpful to know what does work.

Thanks,
DrChuck

[dkeav]

yes it works just fine, im using a nforce chipset with a dual core amd, i doubt the motherboard brand/chipset is the issue, and more likely either the cooler or thermal paste issue, or a buggy acpi