64 bit kernel benefit?

[vmachiel]

Hi,

I've got an 2010 MBP. (core i5, 4 GB RAM) I read somewhere that 10.6 boots with a 32-bit kernel by default, but you can choose to boot in 64 bit. I don't know that much about it, but my understanding is that it has something to do with the amount of memory the system can use.

So will I get a faster machine by booting with the 64-bit kernel and how do I do this by default? (so not the 6 and 4 key every time)

Thanks!