A friend just told me about this little free application that forces your Snow Leopard, 64bit enabled mac to switch its kernel and extension mode to 64 bit (on boot). I have a MacBookPro with Core2Duo Cpu 2.33 (it is pure 64 bit). Unfortunately after running this utility + reading comments and notes on the developer's page , I saw that for some reason apple has restricted EFI in 32bit mode, meaning preventing my kernel to purely run on 64 + extensions. According to a note, it seems that most probably a hardware driver can not support 64 bit mode, so Apple restricts anyway in 32. A bit disappointed I have to admit, for my old but decent MacBookPro!