Motorola 68040 Thermal Plots

Here are some graphs of the temperatures of different processor types at different speeds, and with different cooling devices vs. time.

The temperatures were monitored with a Fluke 51 Thermocouple Thermometer. A K-type Chromel-Alumel thermocouple was used. The thermocouple was attached to the center of the heatsink with transistor silicone grease. Temperatures were observed every 60 seconds.
Keep in mind that these are not temperatures for the processor itself. They are temperatures of heatsink attached to the processors. The temperature of the processor itself will be hotter.
The processors were not idle during these measurements.


Processor: 68040RC25
Running at: 40MHz
Heatsink: Aavid, 0.600 inch
Mounting: Thermal Grease and Clip


Processor: 68040RC33
Running at: 33MHz
Heatsink: Aavid, 0.600 inch
Mounting: Thermal Grease and Clip


Processor: 68040RC33
Running at: 42MHz
Heatsink: Aavid, 0.600 inch
Mounting: Thermal Grease and Clip


Processor: 68040RC25
Running at: 33MHz
Heatsink: 0.250 inch with a Fan mounted on it
Mounting: Thermal Heat Transfer Tape


Processor: 68040RC25
Running at: 40MHz
Heatsink: 0.250 inch with a Fan mounted on it
Mounting: Thermal Heat Transfer Tape


This page is written and maintained by Marc Schrier (schrier@mac.com)