Does my processor support 64bit kernel?

[Mayuresh <mayuresh%acm.org@localhost>]

I am using NetBSD i386 on my desktop. Just want to cross check whether my
processor is 64bit and whether I could use 64 bit system instead of 32
bit.


dmesg describes the processor as follows:

cpu0 at mainbus0 apid 0: Intel(R) Pentium(R) D CPU 3.00GHz, id 0xf65
cpu1 at mainbus0 apid 1: Intel(R) Pentium(R) D CPU 3.00GHz, id 0xf65


1. Is there any way (either some system information command or
manufacturer web page) that can confirm whether above is a 64 bit
processor or not?  I tried on intel site, though searching by above id
(0xf65) didn't help much.

Wikipedia describes this as a 64 bit processor, though since there is no
exact processor Id I am not sure whether to rely on this page:
http://en.wikipedia.org/wiki/Pentium_D


2. Which sets shall I use for an Intel 64 bit processor - amd64? A bit
worried since wikipedia page below says there are differences between
amd64 and intel 64
http://en.wikipedia.org/wiki/Intel_64#Intel_64


3. Is there any perceivable performance gain on a 64 bit processor, with
64 bit system as against 32 bit system? (I'd like to give it a try
irrespective of that, though just thought of asking.)


Mayuresh.