My computer keeps crashing

Jason Henson jason at
Fri Jan 21 05:14:18 PST 2005

On 01/21/05 04:41:45, cali wrote:
>>> Sometimes when I run CPU intensive applications  the system will
>>> crash at seemingly unpredictable times, I have to hard reset the   
>>> machine as it
>>> is completely unresponsive, I was running an experiment in console   
>>> mode and it showed me the kernel panic:
>> With those uptimes I would say your heat sink and fan(hsf) is to  
>> blame. The old idea about amds running hot is kind of crap, any cpu  
>> will run  hot if not installed correctly or overclocked.  You got  
>> that white  stuff between the cpu and hsf?
> I think I recall putting the white stuff in.
>> I checked your hsf on the net and in silent mode it does not support   
>> your cpu speed, though it does in normal higher speed fan mode.  If  
>> you  have the fan make sure to keep it in normal mode or it may bake  
>> your  cpu!  
> Damn! I should have researched this properly when I bought the  
> heatsink. Thanks for that information, I'm lucky that you noticed  
> this.
>> Try this command several times after you boot.  Then after you boot   
>> your box do it while under load.
>> sysctl -a|grep thermal
>> That will tell you your cpu temp, you'll need acpi on.  If you did  
>> not  put the hsf on right it will go up and you get problems like  
>> after 5  minutes or less.  I set my bios heat alarm to go off and  
>> set a shutdown  temp too. You might want to check that stuff out in  
>> your bios too.  Go  to and get that pdf on how to install  
>> the hsf, I made a mistake  a month ago when I was switching out cpus  
>> and that was my problem.
>> Everything else looks good, but do you have some case fans?
> OK, I think I had better invest in some, or some better cooling.
>> I moved a  120mm fan over near my cpu and my 100% load temp while  
>> folding droped  about 10C.  I am overclocked and it was maxing out  
>> at about 58C or less.  Now it hardly hits 50C, usaully 48C but it  
>> might go down to 45C  if it is cool in my room.  I wonder how it  
>> will do in the summer? :)
> I used that sysctl command you suggested above and it says 55C-55.5C  
> -- this is for when running underclocked.
> I rebooted, put the CPU speed back to normal, left the fan on its  
> dangerously low setting and then ran the program again, whilst  
> checking the cpu temperature every second with:
> while [ 1 ]; do sysctl -a | grep thermal; sleep 1; done
> I observed the CPU temperature rise from a base of 50C at an  
> approximately steady rate (I should have taken periodic readings too  
> then I could have made a graph or something). It slowed down at about  
> 57C (having took about 3-4 minutes to get there) or so but carried on  
> rising, 58C...58.5C...59C...59.5C... kernel trap 11m33s  
> (unfortunately I was setting up another process to run on another  
> console so I never saw the final temperature).
> This was with CPU thermal throttling enabled and set to 50% in my  
> bios (although I'm not sure at which temperature it enables as it  
> doesn't seem to say)
> I turned the fan up to max, rebooted and ran the program again. The  
> temperature seemed to stabilise around 52C.
> Given this information I think it is highly likely that the  
> temperature hypothesis is correct, and the reason for the crashing.
> Thanks
> cali

At 60C it is supposed to throttle, but I think it just crashes.  I  
think if you put an air duct next to your cpu that runs to a blow hole  
with a big fan you will get real low temps.  The big fan should be  
sucking air out of the case if you do this.

Make sure the hsf is mounted in the proper direction too, or it won't  

If the air leaving your psu is hot you know you need better case  
cooling.  It should be warm, not hot.

Glad I could help.

More information about the freebsd-questions mailing list