the main reason Intels prescot is so bad is marketing
ever since the P6 core (P3, and current P-Ms) hit a wall at 933mhz they had to make a "quick fix" they done this by doubling the pipeline lengh. This made the proccessor less efficent, but made the clock speed great.
clock speed sells. People see 3.2ghz and buy it over a 2ghz amd.
they then hit a wall at 3.4ghz with northwood, and tried the same, cheap pipeline increase on the prescott, which has failed...
also i think the ALU's in the CPU are double pumped, ie in a 3.2ghz CPU they run at 7.4ghz...thats HOT stuff.
However, in the backround, developing behind the desktop team, the mobile team have "fixed" the P6 core and we now have a VERY VERY good CPU in the P-M, 2ghz, 2mb cache and much faster than Prescott, and even beats A64's However, intel continues to push prescott for some unknown reason?