Core 2 Duo and speed of computations

[Lßbos ElemÚr]

Dear Seqfans,
Did somebody [among you] worked
with PC including new Core 2 Duo CPU
claimed to be quick.
Did somebody compared spewcifically
for mathenatical computations
PC with P4-3GHz
and
PC with Core2Duo 2.1GHz processzor..

Is this new CPU quicker despite of lower frequency
at mathematical purposes or it is quicker
only in games or media performances...?

My problem to decide buying new processor
machine with lower frequncy or old P4 machine
with higher ,3GHz frequency.
Aims are quick  mathematical computations...
This is a dilemma because it might happen to
get a worse machine for higher price...

Have somebody comparative experience with 
this new product ?

Yours 
Labos E
product