Objective MacBook Pro Heat Measurements

Much has been made about the operating temperature of the new MacBook Pro. We noted that their temperature seemed to be on the high side when we reviewed pre-production models at Macworld back in January. In last month's Hands-on Review, we also commented subjectively that our new MacBook Pro gets very warm when doing something CPU and graphics intensive. But it does not seem to be any warmer under that load than our first generation 867MHz 12" PowerBook G4. Generally, ours feels like it runs about as warm as our last three 17" PowerBook G4s (1.0GHz, 1.5GHz and 1.67GHz).

The latest buzz is that the relatively high heat produced by some MacBook Pros may be due to excessive thermal paste being applied during manufacture around the CPU, graphics chip and Northridge chip where they contact the heat pipe system--see this forum entry with photos. We don't have an instrument like that shown in the photos but last week two software applications were released that allow measurement of the MacBook Pro's CPU temperature, InCrew's SpeedIt v0.32R58 kernel extension and Marcel Bresink's Temperature Monitor 3.6.

We used SpeedIt along with Temperature Monitor to measure the CPU temperature of our 15" MacBook Pro. We also used Temperature Monitor alone to measure the temperature of the CPU bottomside of our 867MHz 12" PowerBook G4, one of the hottest (literally) of the PowerBook G4s. If you have trouble getting SpeedIt from InCrew's download page, here is the direct download link.

Our MacBook Pro was set up to drive our 30" Cinema Display with the screen closed and AC adapter plugged in to maximize temperatures. Right out of sleep, our MacBook Pro's 2.16GHz Intel Core Duo CPU registered 18-20^oC. The measured CPU temperature rose to fluctuate between 56-57^oC while at idle, i.e. doing nothing. During routine use such as typing up this article or Web surfing the temperature fluctuated between 56-60^oC. Running Steve Jobs' 2006 Macworld Keynote on QuickTime yielded temperatures of 56-58^oC. Playing a couple of hours of Call of Duty gave temperature spikes of 70-72^oC but mostly it hovered around 60-64^oC.

With the screen open at full brightness, however, our MacBook Pro ran hotter by several degrees: 58-60^oC at idle and 60-63^oC during routine use, including running Steve Jobs' 2006 Macworld Keynote on QuickTime.

Under the same conditions, our 12" PowerBook G4 ran a bit cooler at idle (50-51^oC) and running Steve Jobs' 2006 Macworld Keynote on QuickTime (57-58^oC).

In summary, the 2.16 Intel Core Duo CPU in our MacBook Pro runs hotter by several degrees than the 867MHz G4 in our 12" PowerBook G4. However, externally, they feel about the same. Several MacBook Pro temperature measurements using SpeedIt on the web showed consistent 75^oC temperature readings. Ours only spiked to near that level for a very short period under a heavy load but generally ran cooler than 63^oC at the highest. [Bill Fox]