The Intel Centrino was renamed Pentium M for "mobile". My laptop, which I bought in August, is labeled "Intel Centrino". if I were to buy the same model now, the label would be changed, but the CPU would be the same.
Gone are the days when all CPUs could be compared by measuring the number of cycles performed in one second (1Hz=1 cycle/sec, 1MHz=1,000 cycles/sec, 1GHz = 1,000,000 cycles/sec). Different CPUs send different enough amounts of information per cycle to make the old measurement system useless. The old system is like trying to figure who can walk the furthest by counting the number of steps taken, while disregarding stride length.
Now, the only way to tell which CPU is faster is to "benchmark" them. This process is performed by running the same benchmarking software program on each computer one wants to compare. You can find comparisons of many popular models online, at PC magazine websites, or at download.com . Different benchmarking programs tell you about different (sometimes multiple) aspects of the computers' processign capabilities. For example, my husband and I tested my 900 MHz Centrino/Pentium M against his Pentium "4" 1.4 GHz using a benchmarking program called SiSoft Sandra 2004. While the Centrino beat the Pentium "4" with graphics processing (FPU=1253 vs 1197) capabilities, the Pentium "4" performed better than the Centrino in arithmetic (ALU=2825 vs 3917) and multiple data processing (ISSE2= 1603 vs 2143) in rough proportion to the 0.9:1.4 ratio.
Extrapolating from the stats above, a 1.4 GHz Centrino/Pentium M should be beaten by a 2.4Ghz Pentium "4".
M 1.4 vs "4" 2.4 extrapolated figures:
FPU= 1949 vs 2052 (graphics roughly equal)
ALU= 4394 vs 6715 (Pentium "4" 2.4 GHz whomps Centrino/Pentium M 1.4 on arithmetic)
ISSE2= 2494 vs 3674 (Pentium "4" 2.4 GHz whomps Centrino/Pentium M 1.4 on multiple data processing)
My 900 MHz Centrino is pretty fast. The thing that slows you down is WiFi. Yuck.
Anna