-- On 1 Jan 2004 at 10:44, Tim May wrote:
Further, junction-to-case temperature in a ceramic package has a time constant of tens of seconds, meaning, the case temperature reaches something like 98% of its equilibrium value (as wattage reaches, say, 60 watts, or whatever), in tens of seconds.
The time constant for the CPU+plus cooling system is a good deal longer, and in modern CPUs the large mass of the cooling system can result in quite long periods, for example a quarter of an hour, before CPU load results in heat related shut off.
We also used to run CPUs at 125 C ambient
Today's CPUs will generally fail a bit above seventy centigrade. They frequently fail in ways that cause them to draw increased current, eventuallly incinerating the motherboard. To prevent this, always look for the bios option to shut down the motheroboard in the event of CPU overheating. --digsig James A. Donald 6YeGpsZR+nOTh/cGwvITnSR3TdzclVpR0+pr3YYQdkG Uw0lUnQOu8bBc6kOrcDpYZKS0DjzIgrXM9AJSVh2 49rBlWsHg9Teys0ELS5pT26g56P8tEMtp/mQ3eihl