Its fairly easy to find out what brand of processor and its speed on OS X with About This Mac, however finding out the model number has always been frustrating for some people, who perhaps want to upgrade their RAM, or see how old their processor is.
Its fairly easy to find out, fire up Terminal and type this
sysctl -n machdep.cpu.brand_stringAnd theres your processor model given right to you, it should look something similar to.
Intel(R) Core(TM) i5-2520M CPU @ 2.50GHzThen copy and paste the model number (in this case i5-2520M) into Google search, and usually the first link contains all you need to know.
