oh..ok..i knew about the tdp thing ..
i wonder why an i5 comes with 2.5ghz b4 turbo boost and i7 with 2.1 ghz b4 turbo boost..
also my 5 yrs old previous SONY core 2 duo laptop which i sold couple of days back had 2.4 ghz proc speed..
so kind of makes me skeptical that 2.1 ghz is pretty less for an i7..
Clock speed is not the only thing which matters for a CPU's performance. i7 has more no of cores, HT and better instruction sets.
P4 had clocks upto 3.4GHz, still its way behind.