CoolBook adjusts Core Duo voltage and frequency

Summary:Hot on the heels of my story yesterday about undervolting your Core Duo CPU to save on battery and heat comes a nifty piece of shareware. CoolBook is a GUI to control CPU clock speed and voltage. It's like the author was reading my mind!

CoolBook-controller
Hot on the heels of my story yesterday about undervolting your Core Duo CPU to save on battery and heat comes a nifty piece of shareware. CoolBook is a GUI to control CPU clock speed and voltage. It's like the author was reading my mind!

CoolBook is a $10 shareware application for the MacBook and MBP that allows you to adjust the frequency (clock speed) and voltage of Intel Core Duo and Core 2 Duo CPUs.

According to the author's published benchmarks his MacBook (1.83GHz) temperature decreased by as much as 14°C (25.2°F) just by dropping the voltage from 1.2125 V (Apple default) to 0.95 V (the minimum).

Other programs I've convered here before allow you manually control the MacBook and MBP's fan speed which can greatly reduce operating temperatures.

In my experience Core 2 Duo MacBook Pros can run as much as 40°F cooler than Core Duo machines. I don't consider these voltage/frequency/fan tweaking applications necessary on newer C2D machines, but they're practically required for Core Duos. Especially if you want to use your machine on your lap.

As I mentioned yesterday, there is almost no downside to lowering processor voltage other than constant crashing. If your MacBook starts getting crashy, it's easy enough to crank the voltage back up a tad until it's stable again.

Although I still hope that Apple will include fan and temperature threshold control in a future version of the OS, you can rest assured that they'll never allow us to adjust the voltage. But that's what shareware developers are for.

Topics: Apple

About

Jason D. O'Grady developed an affinity for Apple computers after using the original Lisa, and this affinity turned into a bona-fide obsession when he got the original 128 KB Macintosh in 1984. He started writing one of the first Web sites about Apple (O'Grady's PowerPage) in 1995 and is considered to be one of the fathers of blogging.... Full Bio

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