compare Core i3,i5,i7 processors based upon parameters like frequency and fsb speed...?

the i3 is a dual core with 4 threads.

this means that it has 2 physical cores and 4 virtual cores.this is due to hyperthreading which allows each core to have 2 threads to double performance.in applications that can use hyperthreading,pretty much all except gaming,the i3 will perform considerably better than a amd phenom x4 or an amd fx 4100.while in gaming it will perform only slightly better than the x4 and 4100 not due to its threads but due to it's superior architecture.

the i5 is a quad core with 4 threads

this means it has 4 physical cores and 4 virtual cores.it is a regular quad core ,but due to it's superior architecture it surpasses the amd fx 8150 octacore with 8 cores and 8 threads,the amd x6 processors,etc. in threaded applications and in gaming marginally.it does not have 8 threads because it had hyperthreading disabled,there is no way to re-enable it.

the i7 is a quad core with 8 threads.

this means it has 4 physical cores and 8 virtual cores.it is basically an i5 with hyperthreading enabled,it surpasses nearly all processors in threaded applications and in gaming.the excluded processors are the server class processors with up to 32 physical cores and 64 virtual cores.

as far as frequency goes they are all clocked somewhat closely as long as you look in the same series.

the sandbridge family clocks the i3,i5,i7 at 3.1ghz,3.3ghz,3.4ghz.so frequency isn't going to be a deciding factor.

FSB was replaced by DMI

and the DMI for all of them is 5GT/s or gigatransfers per second.so that's not the deciding factor.

so the only deciding factor is the unlocked multiplier on the K and X suffix'd processors and the number of cores.

if you want to be doing browsing,very light gaming,photoshop,etc then the i3 is for you.

if you want to be doing browsing,heavy gaming,some 3d modeling,some animation,some video ediitng then the i5 is for you

if you want to be doing browsing heavy gaming,complex 3d modeling,complex animations,complex calculations,complex video editing, video encoding,etc then the i7 is for you