I am new (registered today) thats y writing reply now:
first i'll take hyperthreading (intel's technology) a single chip works as 2 CPU, other being virtual. but this technology is entirely software dependent. if the software supports multi threads, then aplications can benefit from Hyperthreading, else not. and those who are with P-4 HT processor, can see that the first graph in CPU performance shows the actual CPU, whislt other shows the performance of virual CPU, and always the application load is on Virtual CPU more. unlike Apple MAC's which are truly hyper threaded with 2 physical CPU's rather than 1 physical and other virtual.
Hypertransport is not actually AMD's own invention, as (previously named as LDT - Lightining Data Transfers) was though developed at AMD, but with other hardware vendors, as its actually implemented on printed circuit. the Input/output speed is increased between RAM, Slots and Processor.
now good thing about this is, as this is entirely hardware dependent, every application out of the box can benefit from it, unlike in hyperthreading, only those who can suport multi threads.