. I know this has been somewhat covered before but... Should I be booting into 64-bit Snow Leopard? I have a 2008 Mac Pro with 16GB of memory. I mostly run Photoshop CS4, X-Plane, QuickTime 7 Pro, Compressor and FCP6. I know you hold down the 6 and 4 keys but is anyone using either "Happy Cat", "K64Enabler 1.0.1", or "32- or 64-bit Kernel Startup Mode Selector 1.2.3" to enable 64-bit Snow Leopard? .