The MacBook ’s electric switch to a Core 2 Duo CPU may have produced only modest gains when compared to a like acclivity to the MacBook Pro . But the updated MacBooks do beat their high - power counterparts in one significant area — they run importantly cooler .

Testing by Macworld Lab found that the move from a Core Duo chip to a next - generation Core 2 Duo processor lessen the MacBook ’s external temperature by about 5 degrees , allowing you to actually set this laptop computer upon your lick . The chip swap produce similar results for the unexampled tune of MacBook Pros free in late October , but likely buyers may be more impressed by the new MacBooks ’ logical peak temperature of more or less 95 degree Fahrenheit near the battery .

What we found

Using the same methodology we employed in our MacBook Pro temperature test , we used the airfoil probe of an infrared thermometer to appraise each of the Core 2 Duo - powered MacBooks in two “ blistering spots”—the bar above the F - keys and the area smother the shelling . The mordant 13 - inch 2GHz MacBook peaked at 95 degree in the area near the battery and 100.7 degrees above the keyboard . The white 2GHz MacBook got a small hotter , with high-pitched temperature of 95.4 and 101.5 level , severally . Despite its slower clock speed , the 13 - column inch 1.83GHz MacBook was only slimly cooler at 94.4 and 100.1 degrees .

Compared to the Core Duo MacBooks these model put back , the upshot show a pregnant melioration . The 2GHz MacBook Core Duo heat up to 101.8 and 105.1 degree during our last run — hotter than all three Core 2 duette - powered models .

As with our last run , we assess interior temperature of the Core 2 Duo MacBooks using the free applicationCoreDuoTemp . Results for the black and livid 2GHz MacBooks were identical to those of the Core Duo generation with high temperatures of 167 academic degree . The ashen 1.83GHz MacBook , however , peaked at 163 degrees .

MacBook Core 2 Duo Temperatures

Reference systems initalics .

All results are in Fahrenheit . Click here for results in Celsius . To appraise outside temperatures , we used an infrared thermometer to get readings on the bar above the F - key and the area environ the electric battery on each laptop computer . Temperatures were measure while converting MP3 single file in iTunes . Internal temperatures were recorded using the CoreDuoTemp applications programme ; because the program does not operate on PowerPC - based Macs , we could not use CoreDuoTemp to record the internal temperature of the PowerBook G4.—MACWORLD LAB examination BY BRIAN CHEN

Here ’s another indicator about the not - as - raging carrying out of the new MacBook models : the laptop computer ’s user manual suggest that it ’s coolheaded enough to be used on your lap — at least for a while . harmonise to Apple ’s manual :

The warning in the substance abuser manual for the Core Duo - base MacBook provide a stark contrast .

If 95 level still is n’t cool enough for you — and make no mistake , these machines still experience warm — programmer Magnus Lundholm late releasedCoolBook , an app that reduce heat , buff interference and stamp battery phthisis by allowing MacBook or MacBook Pro users to qualify frequency and voltage of their laptops . We trust to run succeeding temperature run that include this app .

[ Brian Chen is an assistant editor forMacworld . ]