My desktop is running a Quad Core i7-2700K @3.50 GHz
Old Acer Aspire 5920 got upgraded from a Core 2 Duo T5750 @2.00 GHz to a T9500 @2.60 Ghz
Other 2 laptops have soldered CPUs one Dell with an i3-3227U @1.90 GHz and an Acer with an i5-3337U @ 1.80 GHz
Another Dell Vostro that had an i3-2350M @2.30 GHz upgraded to an i7-2630QM @2.00 GHz Hopefully someday I'll get a i7-2860QM (Accepts faster RAM, faster clock speed and more cache) for it.
Maxing out CPUs on laptops is surprisingly fun and makes the laptop usable for a longer period of time as OSs upgrade over time. As long as that laptop doesn't use BGA which is soldered to the mainboard
Just learning as you go is the best approach. Now Check those chipsets and get upgrading CPUs on old laptops, you might be in for a pleasant suprise.