Hey! Im currently using Intel Core i7-7700 (no overclock) and at the intel's site it says that i can use turbo boost to 4.20GHz so i wonder should i enable it or not? Im using the stock cooler btw.
That feature is normally on by default. You can open your task manager and click on performance to see a real time reflection of the CPU's speed. HwMonitor and HwInfo are a couple utilities that remember the min and max levels as well as real time info. You can be gaming and when you're done you can look to one of those to see how your PC was behaving during that session.
You may also see your CPU's speed well below the stock 3.6GHz, so if you are new to tech. specs. don't be surprised if you see it operating at 800MHz(under 1.0GHz).
You may also hear of Nvidia's GPU Boost technology. It operates similarly in that it can throttle back when the game's needs aren't that taxing but it(GPU Boost) will also "OC" past stock clock speeds depending on the card's behavior. The same way a a veteran OC'er can see voltages, memory and clock speeds and temperature readings and decide based on that information whether or not they can OC a little or a lot more. GPU Boost does that for the user meaning the amount that the user can OC has been reduced because the card does some of the work for them.