Pentium 4-560 Thermal Problems
Tom's Hardware Guide Processors: The P4-560's Heat Can Crash and Kill - The Heat Can Cause Intel's P4 To Throttle And Damage Over Time. An interesting study. Basically, the new Prescott runs so close to its thermal limits that if you install it into a stock system with their thermal "pad" everything is OK.
But, if you use standard thermal compound, it will throttle back and not run at peak efficiency. You need this special silver thermal compound. Why? Well, the main problem is that these new Prescotts are so hot that they are very sensitive to the thermal limits. Also, the internal chassis has to be cool enough at 38 degrees C otherwise, you have the same problem.
Conclusion, if you are a do-it-yourself geek like me, these Prescotts are very touchy.