playing with hyperthreading?

[' =JeffH ']

So I note in the output of cpuid, for my Core 2 T7200 processor..

  Hyper threading siblings: 2

So I'm curious..

1. is it true, this here thing's hyperthreaded?

2. how do I turn it on and off in order to play with it? At this time it's 
off, all indications are that I've only two processors, rather than 4.

I have an account on a 4-core hyperthreaded machine where HT is turned on and 
they're running Debian64 -- that thing screams. oh, yeah, and "top" clearly 
shows 8 "processors".

thanks,

=JeffH

ps: yes, I know that HT won't necessarily make things run faster and might 
slow some stuff down.

pps: I'm presently running Edgy 6.10 32bit