HyperPi is a front end for SuperPi that allows for multiple concurrent instances of SuperPi to be run on each core recognized by the system. It is very dependent on CPU to memory to HDD speed. The faster these components the faster it is able to figure out the number Pi to the selected length. For our testing we use the 32M run. This means that each of the four physical and four logical cores for the i7 (four total on the PII x4 955 and Core i5) is trying to calculate the number Pi out to 32 million decimal places. Each "run" is a comparative to ensure accuracy, and any stability or performance issues in the loop mentioned above will cause errors in calculation.
Here we see HyperPi scaling nicely with the added CPU and memory speeds, up to a maximum speed of 5250MHz.
A poor core (number 4) and a potentially below par memory controller on the chip were holding back a number of these results under Windows 7.