My MacOS X

Run the following command in Terminal to see exactly how many of OS X’s extensions are 64-bit and how many are still 32-bit and shows ppc kexts as well.

file /System/Library/Extensions/*.kext/Contents/MacOS/* | perl -nle 'print $1 if /\((.*)\)/' | sort | uniq -c

Above  command will take a few seconds to run.

Comparison between 10.5.8 and 10.6.0.
10.5.8

109 for architecture i386
106 for architecture ppc
3 for architecture ppc7400


10.6.0

135 for architecture i386
38 for architecture ppc
127 for architecture x86_64


You can also look at “Extensions” in the “Software” section of the System Profiler utility. (Select Apple Menu->About This Mac and then click “More Info”). One of the columns shows whether the .kext is 64-bit capable. Only those extensions that are not 64-bit will show up with a “No” in that column.

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