7 Replies Latest reply: Mar 15, 2013 9:21 AM by Kappy
adam79 Level 1 (0 points)

I just did a clean install of Snow Leopard. When installing applications/software, should I choose the 32bit or 64bit versions?




  • Kappy Level 10 (265,951 points)

    If there are two versions then choose 64-bit, but it doesn't make any difference which you use as both will run in Snow Leopard.

  • adam79 Level 1 (0 points)

    Kappy wrote:


    If there are two versions then choose 64-bit, but it doesn't make any difference which you use as both will run in Snow Leopard.


    I'm only asking because I opened up the Activity Monitor to compare Firefox and Safari; Firefox runs really slow with Snow Leopard compared to Leopard. In the "Kind" column, it says "Intel 64bit" for all the programs. Is Snow Leopard a 32bit OS? Also, why choose 64bit if it doesn't make a difference? Thanks.

  • nickee812 Level 1 (5 points)

    How to find out your bit?


    You can press the Apple Logo when logged in, then press "About This Mac" and then "More Info".


    Then check out this article over here!



  • adam79 Level 1 (0 points)

    Wierd.. I have a 64 bit processor (Intel Core 2 Duo) but the 64-bit Kernel and Extensions is marked "No"

  • Kurt Lang Level 8 (36,670 points)

    By default, Snow Leopard boots with a 32 bit kernel. However, the rest of the OS is 64 bit, and runs as such.


    If you want the OS to boot to the 64 bit kernel, assuming your Mac supports it, hold down the 6 and 4 keys as the Mac starts up. Then check the System Profiler. If it says "Yes", then your Mac supports a 64 bit kernel. If it continues to say "No", then it doesn't.


    A "No" doesn't prevent you from running 64 bit apps. If you want SL to startup as 64 bit all the time without having to hold keys down, do this:


    Here's the configuration file approach for always booting into 64-bit. This is the best way to make your Mac always start up 64 bit as the only thing necessary is to alter one line of a configuration file. You can do that by opening the Terminal and entering the following line. You can also copy/paste it from here into the Terminal window.


    sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.Boot 'Kernel Flags' 'arch=x86_64'


    To return to 32 bit mode, you would repeat the command but enter an empty string, which would just be the single quotes (where arch=x86_64 is) with nothing in between.


    sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.Boot 'Kernel Flags' ''

  • Kappy Level 10 (265,951 points)

    No, Snow Leopard is 64-bit and 32-bit.


    I did not say performance was the same. I said you can run either in Snow Leopard. Depending on the application some run faster in 64-bit mode and some run faster in 32-bit mode. The choice is really not up to you, so to speak. A 32-bit program runs in 32-bit mode while a 64-bit program runs in 64-bit mode. The latter can be forced to run in 32-bit mode.