How To Enable 64-bit mode on Macbook (Snow Leopard)

I have Snow Leopard upgraded on my Macbook since last year & was ecstatic with it’s speed. However I recently discovered that 64-bit mode of the kernel is turned off by default. Finally I found the solution after googling. Please follow this steps:

1. In Terminal:

ioreg -l -p IODeviceTree | grep firmware-abi

If this says “EFI32”, you are done don’t read further. Your hardware doesn’t support 64 bit. If it says “EFI64”; go to Next step.

2. Spotlight ‘Activity Monitor’ & check ‘Kind’ column; if all of the processes just say “Intel” you are running kernel in 32 bit mode.

3. Edit /Library/Preferences/SystemConfiguration/com.apple.Boot.plist as a root, and update following entry.

<string>Kernel Flags</string>
<string></string>

to

<string>Kernel Flags</string>
<string>arch=x86_64</string>

4. You are done; Restart & repeat step 2. You will notice that lot of processes are taking advantage of the Intel 64 architecture.

5. And you will notice speed escalated for the applications.