yep hyperthreading is intels "multi-tasking" so you can do multiple things at the same time e.g. two instances.
AMD sort of has this, as mekano said and you asked why do intel and AMD numbers not match up. A 3200+ (in your case 3300+) is less Ghz than an intel but the equivilent of say a 3.2 (your other machine). More gets done per cycle in an AMD so to a normal user this appears multitasking though it actually is just doing lots of separate things in rapid sucession. Whereas Intel in my knowledge divides the CPU so you could run 2 instances of SOB or Ubero and get 50% each.
Running 2 instances on an AMD doesn't work as the first open client gets the work and due to DC until it runs out of work will keep this priority.
(That is slightly simplified)

hope this makes sense.