Excellent link but the story is a little more complicated for the end-user than what Phil Taylor explicitly states.
We all have to ask ourselves if we have a "Hyperthreaded Enabled Processor" and a motherboard with a "HT Technology enabled Chipset" installed to take advantage of the performance improvements and throughput gains that Phil Taylor describes!!
By examining the BIOS this can quickly be determined as Hyperthreading is enabled in the BIOS. If the line does not appear you do have not a Hyperthreaded Processor!
I discovered last year that I had to wait for a suitable cost effective processor to become available.
I would draw your attention to the following link to Intels site that might well be most helpful to those who want to take advantage of all the hyperthreading facilities in SP1.
http://www.intel.com/products/ht/hyp...c_requirements
Hope this helps!
Bill.