Perhaps a better way would be to have two arrays of data (clock cycles and temperature). The point on the curve that has a significant spike (no longer linear) is the point most likely where the operational ceiling of the chipset is.

The Droid uses the 3430 chipset and most tests suggest that once you pass 1.1 ghz, the temps spike by up to ten degrees and apps begin to freeze. There are very few reports of issues at 900mhz to 1ghz and virtually no issues at 800mhz.

But as Flandry already mentioned, the design for heat dissipation is a caveat when comparing the Droid and N900.