Mega Hertz... what Mega Hertz ?
The 90 nm Prescott is expected to reach speeds of 4 GHz and beyond. The Integer Execution Units however runs at 8 GHz, so does the integer register file, the address generators and now, as we may presume, also the L1 data cache. So why call it a 4 GHz processor? Technically spoken it is not a 4 GHz processor but an 8 GHz processor...
A Chance for a Change
Such a sudden jump in Giga Hertz needs to be accompanied with a significant increase in performance to make it marketable to the average customer. The 50% ... 60% extra performance brought by improved Simultaneous Multi Threading does offer this as a one-time-only opportunity. If Intel ever wants to use the real frequency of the Integer Pipeline then it has to make the transition with the introduction of the Prescott.
A name change to Pentium 5 would be appropriate to signal a major architecture change.
Marketing and Metaphors
To marketing the task to explain the term simultaneous multi threading to the general public. Most likely ending up with a number of metaphors that give people the illusion that they understand something while they are in fact totally confusing reality. We've heard a few nice ones from AMD when it had to explain that Mega Hertz is not the same as performance. Something like "Animals with little legs having to run like crazy just to keep up with the larger (Athlon) species...." The classical combustion engine may help here: "A four cylinder engine with twice the RPM produces the same amount of Horse Powers as an eight cylinder does ...." The extra complication is to explain how the second logical processor is result of the much higher frequency. " The processor is so incredible fast that it can work like two", Something like the energetic modern women who have a job and take care of their children at the same time... I would not be surprised that as a side effect of such a campaign we may see some psychiatric researchers proposing that raised brain wave frequencies can induce schizophrenia...
Well, for so far the hope that marketing can produce some decent consumer education...
An 8 GHz Processor in a 90 nm process would be consistent with Intel's statements that it's 70 nm processors will run at more then 10 GHz. These predictions were made already one and a halve year ago.
http://www.chip-architect.com/news/2002_04_16_Prescott_Prospects_.html
I can see the head lines now:
PR Ratings in PIV processors to combat XP Ratings by AMD