BigDiver

So far I have noticed a huge difference in the temperature of the Air. After playing with CoolBook for a bit, getting a few system hangs and one kernel panic, i found the following settings to be stable:

Adapter:
1200 MHz 0.9000 V
1400 MHz 0.9875 V
1600 MHz 0.9875 V

Battery
800 MHz 0.9000 V
1200 MHz 0.9750 V

Throttling: High
Temp Limit: 85 C

Video plays with no hiccups and so far temperature has not climbed over 70C.

It has been reported many times that the Macbook Air overheats to the point of burning your legs. On the positive side we could possibly use it on the next corporate BBQ to get some ribs grilled to perfection.

It has been my experience that the fastest way to get the Air burning is to have it play some HD video. After a few minutes the playback starts hanging, the CPU goes to 100%, and that is the end of the movie.

I knew that undervolting could be a solution but I did not know how to use it on the Mac
Undervolting is basically a process to lower the CPU voltage by software in order to improve battery consumption and lower operating temperatures.

Due to the manufacturing processes each CPU has slightly different voltage tolerances. Chip manufacturers, instead of optimizing de lowest voltage possible for each individual CPU, they basically set it to a know stable configuration, that some times is far from optimal.

The higher the voltage the higher the power dissipation, i.e. heat generated by the CPU. This has nothing to do with speed. Do not confuse voltage with frequency and clock cycles. Lowering the voltage will not make your computer run slower, or damage your CPU in any way. It will save battery and cool it down.
The idea is to lower the CPU voltage while keeping the frequency at its maximum.

The “risk” of lowering the CPU voltage is instability, again you will not, repeat not, damage the CPU. At a certain point the CPU will be unstable and cause a kernel panic in the operating system. So all you need to to is find the lower possible voltage that still keeps the CPU stable and you have a winning configuration.

After searching the Web for days on end I found a cool (no pun intended) small utility called CoolBook that allows you to do just that, play with your voltage settings in order to find the optimal lowest voltage for your CPU to run.

I have been playing with CoolBook for a day or so and I will report back my findings soon.

What has been your experience with Mac Overheating problems?