I encountered many freezes since I upgraded to Snow Leopard. (Beachball appeared for about 20 seconds and the GUI didn’t respond) Yesterday I found the problem. So if you have those freezes too, and you have installed Growl (maybe it came with Adium or something), deactivate Growl in your System Preferences or install one of the Growl betas.

//Update: Growl seems to be not the only problem. When using Safari freezes occur sometimes too… in /etc/log/System.log something like “INSERT-HANG-DETECTED” shows up. Hope they fix those freezing issues soon. Some people reported booting in 64bit mode solves the problems…

//Update: booting to 64Bit solved the freezing issues for me. (Hold 6 and 4 while your mac starts up, you can release the keys if the spinning wheel appears)

//See newer update at the end of this post!

For booting in 64bit permanently you have to edit com.apple.Boot.plist this only works if you have 64bit efi, to test if you have 64bit efi type this in terminal.app: ioreg -l -p IODeviceTree | grep firmware-abi

If you have efi64 you can make it permanently boot in 64Bit:

1. Open Terminal.app
2. enter: sudo pico /Library/Preferences/SystemConfiguration/com.apple.Boot.plist
3. search for
<key>Kernel Flags</key>
<string></string>
4. replace it with:
<key>Kernel Flags</key>
<string>arch=x86_64</string>
5. press ctrl+o
6. press enter

//update: a few days after booting in 64bit the freezes came back… but I think this finally did the trick : http://support.apple.com/kb/HT1411 Since I did this SMC Reset on my Macbook Pro 13″ (current generation) everything seems to work perfect (even Safari!!)

//update: in the meantime apple released the so called “performance update” which seems to care about the freezes too. If the last steps didn’t help you don’t bother installing it.

written by Andreas Hegenberg