Not true. If a cpu is using the same die size, same architecture, and same materials, the one that is already rated to run faster is going to run hotter, period. By bringing a chip up to equivalent speeds, with just a little extra money for cooling, you may or may not exceed that temperature. If the cpu is only a few degrees hotter, it won't make that big of a difference. And even if it was a good 10, maybe 15 degrees hotter, it still is a moot point - The life of the CPU is most likely still far beyond the amount of time you would own your system.